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Abstract:

A high strength and high conductivity copper alloy pipe, rod, or wire is
composed of an alloy composition containing 0.13 to 0.33 mass % of Co,
0.044 to 0.097 mass % of P, 0.005 to 0.80 mass % of Sn, and 0.00005 to
0.0050 mass % of O, wherein a content [Co] mass % of Co and a content [P]
mass % of P satisfy a relationship of
2.9≦([Co]-0.007)/([P]-0.008)≦6.1, and the remainder
includes Cu and inevitable impurities. The high strength and high
conductivity copper alloy pipe, rod, or wire is produced by a process
including a hot extruding process. Strength and conductivity of the high
strength and high conductivity copper pipe, rod, or wire are improved by
uniform precipitation of a compound of Co and P and by solid solution of
Sn.

Claims:

1. A high strength and high conductivity copper alloy pipe, rod, or wire,
produced by a process including a hot extruding process, having an alloy
composition comprising: 0.13 to 0.33 mass % of Co; 0.044 to 0.097 mass %
of P; 0.005 to 0.80 mass % of Sn; and 0.00005 to 0.0050 mass % of O,
wherein a content [Co] mass % of Co and a content [P] mass % of P satisfy
a relationship of 2.9.ltoreq.([Co]-0.007)/([P]-0.008)≦6.1; and the
remainder includes Cu and inevitable impurities.

2. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein the alloy composition further
comprises at least any one of 0.003 to 0.5 mass % of Zn, 0.002 to 0.2
mass % of Mg, 0.003 to 0.5 mass % of Ag, 0.002 to 0.3 mass % of Al, 0.002
to 0.2 mass % of Si, 0.002 to 0.3 mass % of Cr, and 0.001 to 0.1 mass %
of Zr.

3. A high strength and high conductivity copper alloy pipe, rod, or wire,
produced by a process including a hot extruding process, having an alloy
composition comprising: 0.13 to 0.33 mass % of Co; 0.044 to 0.097 mass %
of P; 0.005 to 0.80 mass % of Sn; 0.00005 to 0.0050 mass % of O; at least
any one of 0.01 to 0.15 mass % of Ni and 0.005 to 0.07 mass % of Fe,
wherein a content [Co] mass % of Co, a content [Ni] mass % of Ni, a
content [Fe] mass % of Fe, and a content [P] mass % of P satisfy a
relationship of
2.9.ltoreq.([Co]+0.85.times.[Ni]+0.75.times.[Fe]-0.007)/([P]-0.008).ltore-
q.6.1 and a relationship of
0.015.ltoreq.1.5.times.[Ni]+3.times.[Fe]≦[Co]; and the remainder
includes Cu and inevitable impurities.

4. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein the alloy composition further
comprises at least any one of 0.003 to 0.5 mass % of Zn, 0.002 to 0.2
mass % of Mg, 0.003 to 0.5 mass % of Ag, 0.002 to 0.3 mass % of Al, 0.002
to 0.2 mass % of Si, 0.002 to 0.3 mass % of Cr, 0.001 to 0.1 mass % of
Zr.

5. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein a billet is heated to 840 to
960.degree. C. before the hot extruding process, and an average cooling
rate from 840.degree. C. after the hot extruding process or a temperature
of an extruded material to 500.degree. C. is 15.degree. C./second or
higher, and wherein a heat treatment at 375.degree. C. to 630.degree. C.
for 0.5 to 24 hours is performed after the hot extruding process, or is
performed before and after a cold drawing/wire drawing process or during
the cold drawing/wire drawing process when the cold drawing/wire drawing
process is performed after the hot extruding process.

6. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein substantially circular or
substantially oval fine precipitates are uniformly dispersed in the
copper alloy, and wherein an average grain diameter of the precipitates
is 1.5 to 20 nm, or at least 90% of the total precipitates have a size of
30 nm or less.

7. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein an average grain size at the time of
completing the hot extruding process is 5 to 75 μm.

8. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 5, wherein when a total processing rate of the
cold drawing/wire drawing process until the heat treatment after the hot
extruding process is higher than 75%, a recrystallization ratio of matrix
in a metal structure after the heat treatment is 45% or lower, and an
average grain size of a recrystallized part is 0.7 to 7 μm.

9. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein a first ratio of minimum tensile
strength/maximum tensile strength in variation of tensile strength in an
extruding production lot is 0.9 or higher, and a second ratio of minimum
conductivity/maximum conductivity in variation of conductivity is 0.9 or
higher.

10. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein conductivity of the copper alloy is 45
% IACS or higher, and a value of R1/2.times.S×(100+L)/100
is 4300 or more, where R (% IACS) is conductivity, S (N/mm2) is
tensile strength, and L (%) is elongation.

11. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein the tensile strength of the copper
alloy at 400.degree. C. is 200 N/mm2 or higher.

12. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein Vickers hardness (HV) after heating at
700.degree. C. for 120 seconds is 90 or higher, or at least 80% of the
Vickers hardness before the heating, and an average grain diameter of
precipitates in a metal structure after the heating is 1.5 to 20 nm, or
at least 90% of the total precipitates have a size of 30 nm or less, and
a recrystallization ratio in the metal structure after the heating is 45%
or lower.

13. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 1, wherein the copper alloy pipe, rod or wire is
cold forged or pressed.

14. The high strength and high conductivity copper alloy wire according
to claim 1, wherein a cold wire drawing process or a pressing process is
performed on the alloy composition, and a heat treatment at 200 to
700.degree. C. for 0.001 seconds to 240 minutes is performed during the
cold wire drawing process or the pressing process and/or after the cold
wire drawing process or the pressing process.

15. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein a billet is heated to 840 to
960.degree. C. before the hot extruding process, and an average cooling
rate from 840.degree. C. after the hot extruding process or a temperature
of an extruded material to 500.degree. C. is 15.degree. C./second or
higher, and wherein a heat treatment at 375.degree. C. to 630.degree. C.
for 0.5 to 24 hours is performed after the hot extruding process, or is
performed before and after the cold drawing/wire drawing process or
during the cold drawing/wire drawing process when a cold drawing/wire
drawing process is performed after the hot extruding process.

16. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein a billet is heated to 840 to
960.degree. C. before the hot extruding process, and an average cooling
rate from 840.degree. C. after the hot extruding process or a temperature
of an extruded material to 500.degree. C. is 15.degree. C./second or
higher, and wherein a heat treatment at 375.degree. C. to 630.degree. C.
for 0.5 to 24 hours is performed after the hot extruding process, or is
performed before and after the cold drawing/wire drawing process or
during the cold drawing/wire drawing process when a cold drawing/wire
drawing process is performed after the hot extruding process.

17. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein a billet is heated to 840 to
960.degree. C. before the hot extruding process, and an average cooling
rate from 840.degree. C. after the hot extruding process or a temperature
of an extruded material to 500.degree. C. is 15.degree. C./second or
higher, and wherein a heat treatment at 375.degree. C. to 630.degree. C.
for 0.5 to 24 hours is performed after the hot extruding process, or is
performed before and after the cold drawing/wire drawing process or
during the cold drawing/wire drawing process when a cold drawing/wire
drawing process is performed after the hot extruding process.

18. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein substantially circular or
substantially oval fine precipitates are uniformly dispersed in the
copper alloy, and wherein an average grain diameter of the precipitates
is 1.5 to 20 nm, or at least 90% of the total precipitates have a size of
30 nm or less.

19. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein substantially circular or
substantially oval fine precipitates are uniformly dispersed in the
copper alloy, and wherein an average grain diameter of the precipitates
is 1.5 to 20 nm, or at least 90% of the total precipitates have a size of
30 nm or less.

20. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein substantially circular or
substantially oval fine precipitates are uniformly dispersed in the
copper alloy, and wherein an average grain diameter of the precipitates
is 1.5 to 20 nm, or at least 90% of the total precipitates have a size of
30 nm or less.

21. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein an average grain size at the time of
completing the hot extruding process is 5 to 75 μm.

22. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein an average grain size at the time of
completing the hot extruding process is 5 to 75 μm.

23. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein an average grain size at the time of
completing the hot extruding process is 5 to 75 μm.

24. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein a first ratio of minimum tensile
strength/maximum tensile strength in variation of tensile strength in an
extruding production lot is 0.9 or higher, and a second ratio of minimum
conductivity/maximum conductivity in variation of conductivity is 0.9 or
higher.

25. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein a first ratio of minimum tensile
strength/maximum tensile strength in variation of tensile strength in an
extruding production lot is 0.9 or higher, and a second ratio of minimum
conductivity/maximum conductivity in variation of conductivity is 0.9 or
higher.

26. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein a first ratio of minimum tensile
strength/maximum tensile strength in variation of tensile strength in an
extruding production lot is 0.9 or higher, and a second ratio of minimum
conductivity/maximum conductivity in variation of conductivity is 0.9 or
higher.

27. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein conductivity of the copper alloy is
45% IACS or higher, and a value of R1/2.times.S×(100+L)/100 is
4300 or more, where R (% IACS) is conductivity, S (N/mm2) is tensile
strength, and L (%) is elongation.

28. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein conductivity of the copper alloy is
45% IACS or higher, and a value of R1/2.times.S×(100+L)/100 is
4300 or more, where R (% IACS) is conductivity, S (N/mm2) is tensile
strength, and L (%) is elongation.

29. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein conductivity of the copper alloy is
45% IACS or higher, and a value of R1/2.times.S×(100+L)/100 is
4300 or more, where R (% IACS) is conductivity, S (N/mm2) is tensile
strength, and L (%) is elongation.

30. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein Vickers hardness (HV) after heating at
700.degree. C. for 120 seconds is 90 or higher, or at least 80% of the
Vickers hardness before the heating, and an average grain diameter of
precipitates in a metal structure after the heating is 1.5 to 20 nm, or
at least 90% of the total precipitates have a size of 30 nm or less, and
a recrystallization ratio in the metal structure after the heating is 45%
or lower.

31. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein Vickers hardness (HV) after heating at
700.degree. C. for 120 seconds is 90 or higher, or at least 80% of the
Vickers hardness before the heating, and an average grain diameter of
precipitates in a metal structure after the heating is 1.5 to 20 nm, or
at least 90% of the total precipitates have a size of 30 nm or less, and
a recrystallization ratio in the metal structure after the heating is 45%
or lower.

32. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein Vickers hardness (HV) after heating at
700.degree. C. for 120 seconds is 90 or higher, or at least 80% of the
Vickers hardness before the heating, and an average grain diameter of
precipitates in a metal structure after the heating is 1.5 to 20 nm, or
at least 90% of the total precipitates have a size of 30 nm or less, and
a recrystallization ratio in the metal structure after the heating is 45%
or lower.

33. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 2, wherein the copper alloy pipe, rod or wire is
cold forged or pressed.

34. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 3, wherein the copper alloy pipe, rod or wire is
cold forged or pressed.

35. The high strength and high conductivity copper alloy pipe, rod, or
wire according to claim 4, wherein the copper alloy pipe, rod or wire is
cold forged or pressed.

Description:

TECHNICAL FIELD

[0001] The present invention relates to a high strength and high
conductivity copper alloy pipe, rod, or wire produced by processes
including a hot extruding process.

BACKGROUND ART

[0002] Copper having excellent electrical and thermal conductivity has
been widely used in various kinds of industrial field as connectors,
relays, electrodes, contact points, trolley lines, connection terminals,
welding tips, rotor bars used in motors, wire harnesses, and wiring
materials of robots or airplanes. For example, copper has been used for
wire harnesses of cars, and weights of the cars need to be reduced to
improve fuel efficiency regarding global warming. However, the weights of
used wire harnesses tend to increase according to high information,
electronics, and hybrids of the car. Since copper is expensive metal, the
car manufacturing industry wants to reduce the amount of copper to be
used in view of the cost. For this reason, if a copper wire for a wire
harness which has high strength, high conductivity, flexibility, and
excellent ductility is used, it becomes possible to reduce the amount of
copper to be used thereby allow achieving a reduction in weight and cost.

[0003] There are several kinds of wire harnesses, for example, a power
system and a signal system in which only very little current flows. For
the former, conductivity close to that of pure copper is required as the
first condition. For the later, particularly, high strength is required.
Accordingly, a copper wire balanced in strength and conductivity is
necessary according to purposes. Distribution lines and the like for
robots and airplanes are required to have high strength, high
conductivity, and flexibility. In such distribution lines, there are many
cases of using a copper wire as a stranded wire including several or
several tens of thin wires in structure to further improve flexibility.
In this specification, a wire means a product having a diameter or an
opposite side distance less than 6 mm. Even when the wire is cut in a rod
shape, the cut wire is called a wire. A rod means a product having a
diameter or an opposite side distance of 6 mm or more. Even when the rod
is formed in a coil shape, the coil-shaped rod is called a rod.
Generally, a material having a large outer diameter is cut in a rod
shape, and a thin material comes out into a coil-shaped product. However,
when a diameter or an opposite side distance is 4 to 16 mm, there are
wires and rods together. Accordingly, they are defined herein. A general
term of a rod and a wire is a rod wire.

[0004] A high strength and high conductivity copper alloy pipe, rod, or
wire (hereinafter, referred to as a high performance copper pipe, rod, or
wire) according to the invention requires the following characteristics
according to usage.

[0005] Thinning on the male side connector and a bus bar is progressing
according to reduction in size of the connector, and thus strength and
conductivity capable of standing against putting-in and drawing-out of
the connector is required. Since a temperature rises during usage, a
stress relaxation resistance is necessary.

[0006] In a relay, an electrode, a connector, a buss bar, a motor, and the
like, in which large current flows, high conductivity is naturally
required and also high strength is necessary for compact size or the
like.

[0007] In a wire for wire cut (electric discharging), high conductivity,
high strength, wear resistance, high-temperature strength, and durability
are required.

[0008] In a trolley line, high conductivity and high strength are
required, and durability, wear resistance, and high-temperature strength
are also required during usage. Generally, since there are many trolley
lines having a diameter of 20 mm, the trolley lines fall within the scope
of rod in this specification.

[0009] In a welding tip, high conductivity, high strength, wear
resistance, high-temperature strength, durability, and high thermal
conductivity are required.

[0010] In the viewpoint of high reliability, soldering is not used, but
brazing is generally used for connection among electrical members, among
high-speed rotating members, among members with vibration such as a car,
and among copper materials and nonferrous metal such as ceramics. As a
brazing material, for example, there is 56Ag-22Cu-17Zn-5Sn alloy brazing
such as Bag-7 described in JIS Z 3261. As a temperature of the brazing, a
high temperature of 650 to 750° C. is recommended. For this
reason, in a rotor bar used in a motor, an end ring, a relay, an
electrode, or the like, heat resistance for 700° C. as a brazing
temperature is required even for a short time. Naturally, it is used
electrically, and thus high conductivity is required even after the
brazing. Centrifugal force of the rotor bar used in a motor is increased
by high speed, and thus strength for standing against the centrifugal
force is necessary. In an electrode, a contact point, a relay which is
used in a hybrid car, an electric car, and a solar battery and in which
high current flows, high conductivity and high strength are necessary
even after the brazing.

[0011] Electrical components, for example, a fixer, a brazing tip, a
terminal, an electrode, a relay, a power relay, a connector, a connection
terminal, and the like are manufactured from rods by cutting, pressing,
or forging, and high conductivity and high strength are required. In the
brazing tip, the electrode, and the power relay, additionally, wear
resistance, high-temperature strength, and high thermal conductivity are
required. In these electrical components, brazing is often used as
bonding means. Accordingly, heat resistance for keeping high strength and
high conductivity even after high-temperature heating at, for example,
700° C. is necessary. In this specification, heat resistance means
that it is hard to be recrystallized even by heating at a high
temperature of 500° C. or higher and strength after the heating is
excellent. In mechanical components such as nuts or metal fittings of
faucets, a pressing process and a cold forging process are performed. An
after-process includes rolling and cutting. Particularly, formability in
cold, forming easiness, high strength, and wear resistance are necessary,
and it is required that there is no stress corrosion cracking. In
addition, there are many cases of employing the brazing for connecting
pipes or the like, and thus high strength after the brazing is required.

[0012] In copper materials, pure copper based on C1100, C1020, and C1220
having excellent conductivity has low strength, and thus a using amount
thereof is increased to widen a sectional area of a used part. In
addition, as high strength and high conductivity copper alloy, there is
Cr--Zr copper (1%Cr-0.1%Zr--Cu) that is solution-aging precipitation
alloy. However, this alloy is made into a rod, generally through a heat
treatment process of hot extruding, heating of materials at 950°
C. (930 to 990° C.) again, rapid cooling just thereafter, and
aging, and then it is additionally processed in various shapes. A product
is made through a heat treatment process of a plasticity process such as
hot or cold forging of an extruded rod after hot extruding, heating at
950° C. after the plasticity process, rapid cooling, and aging. As
described above, the high temperature process such as at 950° C.
requires large energy. In addition, since oxidation loss occurs by
heating in the air and diffusion easily occurs due to the high
temperature, sticking among materials occurs and thus a pickling process
is necessary. For this reason, a heat treatment at 950° C. in
inert gas or vacuum is performed, but a cost for the heat treatment is
increased and extra energy is necessary. In addition although it is
possible to prevent the oxidation loss, the problem of the sticking is
not solved. In Cr--Zr copper, a scope of a solution temperature condition
is narrow, and sensitivity of a cooling rate is high. Accordingly, a
particular management is necessary. Moreover, Cr--Zr copper includes a
large amount of active Zr and Cr, and thus there is a limitation in
casting and forging. As a result, characteristics are excellent, but
costs are increased.

[0013] A copper material that is an alloy composition containing 0.15 to
0.8 mass % of Sn and In in total and the remainder including Cu and
inevitable impurities, has been known (e.g., Japanese Patent Application
Laid-Open No. 2004-137551). However, strength is insufficient in such a
copper material.

DISCLOSURE OF THE INVENTION

[0014] The present invention has been made to solve the above-described
problems, and an object of the invention is to provide a low-cost,
high-strength and high-conductivity copper alloy pipe, rod, or wire
having high strength and high conductivity.

[0015] According to a first aspect of the invention to achieve the object,
there is provided a high strength and high conductivity copper alloy
pipe, rod, or wire produced by a process including a hot extruding
process, which is an alloy composition containing: 0.13 to 0.33 mass % of
Co; 0.044 to 0.097 mass % of P; 0.005 to 0.80 mass % of Sn; and 0.00005
to 0.0050 mass % of O, wherein a content [Co] mass % of Co and a content
[P] mass % of P satisfy a relationship of
2.9≦([Co]-0.007)/([P]-0.008)≦6.1, and the remainder
includes Cu and inevitable impurities.

[0016] According to the invention, strength and conductivity of the high
strength and high conductivity copper alloy pipe, rod, or wire are
improved by uniformly precipitating a compound of Co and P and by solid
solution of Sn, and a cost thereof is reduced since it is produced by the
hot extruding process.

[0017] According to another aspect of the invention, there is provided a
high strength and high conductivity copper alloy pipe, rod, or wire
produced by a process including a hot extruding process, which is an
alloy composition containing: 0.13 to 0.33 mass % of Co; 0.044 to 0.097
mass % of P; 0.005 to 0.80 mass % of Sn; 0.00005 to 0.0050 mass % of O;
and at least any one of 0.01 to 0.15 mass % of Ni and 0.005 to 0.07 mass
% of Fe, wherein a content [Co] mass % of Co, a content [Ni] mass % of
Ni, a content [Fe] mass % of Fe, and a content [P] mass % of P satisfy a
relationship of
2.9≦([Co]+0.85×[Ni]+0.75×[Fe]-0.007)/([P]-0.008).ltore-
q.6.1 and a relationship of
0.015≦1.5×[Ni]+3×[Fe]≦[Co], and the remainder
includes Cu and inevitable impurities.

[0018] With such a configuration, precipitates of Co, P, and the like
become fine by Ni and Fe, thereby improving strength and heat resistance
for the high strength and high conductivity copper alloy pipe, rod, or
wire.

[0019] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable to further include at least any one of Zn of
0.003 to 0.5 mass %, Mg of 0.002 to 0.2 mass %, Ag of 0.003 to 0.5 mass
%, Al of 0.002 to 0.3 mass %, Si of 0.002 to 0.2, Cr of 0.002 to 0.3 mass
%, Zr of 0.001 to 0.1 mass %. With such a configuration, S mixed in the
course of recycling a Cu material is made harmless by Zn, Mg, Ag, Al, Si,
Cr, and Zr, intermediate temperature embrittlement is prevented, and the
alloy is further strengthened, thereby improving ductility and strength
of the high strength and high conductivity copper alloy pipe, rod, or
wire.

[0020] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that a billet be heated to 840 to 960°
C. before the hot extruding process, and an average cooling rate from
840° C. after the hot extruding process or a temperature of an
extruded material to 500° C. is 15° C./second or higher,
and it is preferable that a heat treatment TH1 at 375 to 630° C.
for 0.5 to 24 hours be performed after the hot extruding process, or is
performed before and after the cold drawing/wire drawing process or
during the cold drawing/wire drawing process when a cold drawing/wire
drawing process is performed after the hot extruding process. With such a
configuration, an average grain size is small, and precipitates are
finely precipitated, thereby improving strength for the high strength and
high conductivity copper alloy pipe, rod, or wire.

[0021] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that substantially circular or substantially
oval fine precipitates be uniformly dispersed, and it is preferable that
an average grain diameter of the precipitates be between 1.5 and 20 nm,
or at least 90% of the total precipitates have a size of 30 nm or less.
With such a configuration, fine precipitates are uniformly dispersed.
Accordingly, strength and heat resistance are high, and conductivity is
satisfactory.

[0022] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that an average grain size at the time of
completing the hot extruding process be between 5 and 75 μm. With such
a configuration, the average grain size is small, thereby improving
strength for the high strength and high conductivity copper alloy pipe,
rod, or wire.

[0023] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that when a total processing rate of the cold
drawing/wire drawing process until the heat treatment TH1 after the hot
extruding process is higher than 75%, a recrystallization ratio of matrix
in a metal structure after the heat treatment TH1 be 45% or lower, and an
average grain size of a recrystallized part be 0.7 to 7 μm. With such
a configuration, when the total cold working processing rate of the cold
drawing/wire drawing process after the hot extruding process to the
precipitation heat treatment process is higher than 75% in a thin wire, a
thin rod, and a thin pipe, the recrystallization ratio of matrix in the
metal structure after the precipitation heat treatment process is 45% or
lower. When the average grain size of the recrystallized part is 0.7 to 7
μm, ductility, a repetitive bending property is improved without
decreasing the final strength of the high strength and high conductivity
copper alloy pipe, rod, or wire.

[0024] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that a ratio of (minimum tensile
strength/maximum tensile strength) in variation of tensile strength in an
extruding production lot be 0.9 or higher, and a ratio of (minimum
conductivity/maximum conductivity) in variation of conductivity is 0.9 or
higher. With such a configuration, the variation of tensile strength and
conductivity is small, thereby improving quality of the high strength and
high conductivity copper alloy pipe, rod, or wire.

[0025] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that conductivity be 45 (%IACS) or higher, and
a value of (R1/2×S×(100+L)/100) be 4300 or more, where R
(%IACS) is conductivity, S (N/mm2) is tensile strength, and L (%) is
elongation. With such a configuration, the value of
(R1/2×S×(100+L)/100) is 4300 or more, and a balance
between strength and conductivity is excellent. Accordingly, it is
possible to reduce the diameter or thickness of the pipe, rod, or wire,
and thus it is possible to reduce a cost.

[0026] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that tensile strength at 400° C. be 200
(N/mm2) or higher. With such a configuration, high-temperature
strength is high, and thus it is possible to use the pipe, rod, or wire
under a high temperature.

[0027] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that Vickers hardness (HV) after heating at
700° C. for 120 seconds be 90 or higher or at least 80% of the
Vickers hardness before the heating, an average grain diameter of
precipitates in a metal structure after the heating be 1.5 to 20 nm or at
least 90% of the total precipitates have a size of 30 nm or less, and a
recrystallization ratio in the metal structure after the heating be 45%
or lower. With such a configuration, heat resistance is excellent, and
thus it is possible to process and use the pipe, rod, or wire in a
circumstance under a high temperature. In addition, decrease in strength
is small after processing for a short time under a high temperature.
Accordingly, it is possible to reduce the diameter or thickness of the
pipe, rod, or wire, and thus it is possible to reduce the cost.

[0028] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that the pipe, rod, or wire be used for cold
forging or pressing. Since fine precipitates are uniformly dispersed by
cold forging or pressing, strength becomes high and conductivity becomes
satisfactory by process hardening. In addition, even in a press product
and a forged product, high strength is kept in spite of exposure to a
high temperature.

[0029] In the high strength and high conductivity copper alloy pipe, rod,
or wire, it is preferable that a cold wire drawing process or a pressing
process be performed, and a heat treatment TH2 at 200 to 700° C.
for 0.001 seconds to 240 minutes be performed during the cold wire
drawing process or the pressing process and/or after the cold wire
drawing process or the pressing process. With such a configuration,
flexibility and conductivity of the wire are excellent. Particularly,
ductility, flexibility, and conductivity become low when a cold working
processing rate is increased by wire drawing, pressing, or the like, but
ductility, flexibility, and conductivity are improved by performing the
heat treatment TH2. In this specification, good flexibility means that
bending can be repeated more than 18 times in case of a wire having an
outer diameter of 1.2 mm.

BRIEF DESCRIPTION OF DRAWINGS

[0030] FIG. 1 is a flowchart of a producing process K of a high
performance copper pipe, rod, or wire according to an embodiment of the
invention.

[0031] FIG. 2 is a flowchart of a producing process L of the high
performance copper pipe, rod, or wire.

[0032] FIG. 3 is a flowchart of a producing process M of the high
performance copper pipe, rod, or wire.

[0033] FIG. 4 is a flowchart of a producing process N of the high
performance copper pipe, rod, or wire.

[0034] FIG. 5 is a flowchart of a producing process P of the high
performance copper pipe, rod, or wire.

[0035] FIG. 6 is a flowchart of a producing process Q of the high
performance copper pipe, rod, or wire.

[0036]FIG. 7 is a flowchart of a producing process R of the high
performance copper pipe, rod, or wire.

[0037] FIG. 8 is a flowchart of a producing process S of the high
performance copper pipe, rod, or wire.

[0038] FIG. 9 is a flowchart of a producing process T of the high
performance copper pipe, rod, or wire.

[0039] FIG. 10 is a metal structure photograph of precipitates in a
process K3 of the high performance copper pipe, rod, or wire.

[0040] FIG. 11 is a metal structure photograph of precipitates after
heating for 120 seconds at 700° C. in a compression process
material of a process K0 of the high performance copper pipe, rod, or
wire.

BEST MODE FOR CARRYING OUT THE INVENTION

[0041] A high performance copper pipe, rod, or wire according to an
embodiment of the invention will be described. In the invention, a first
invention alloy, a second invention alloy, and a third invention alloy
having alloy compositions in high performance copper pipe, rod, or wire
according to first to fourth aspects are proposed. In the alloy
compositions described in the specification, a symbol for element in
parenthesis such as [Co] represents a content (mass %) of the element.
Invention alloy is the general term for the first to third invention
alloys.

[0042] The first invention alloy is an alloy composition that contains
0.13 to 0.33 mass % of Co (preferably 0.15 to 0.32 mass %, more
preferably 0.16 to 0.29 mass %), 0.044 to 0.097 mass % of P (preferably
0.048 to 0.094 mass %, more preferably 0.051 to 0.089 mass %), 0.005 to
0.80 mass % of Sn (preferably 0.005 to 0.70 mass %; more preferably 0.005
to 0.095 mass % in a case where particular high strength is not necessary
while high electrical and thermal conductivity is necessary, and further
more preferably 0.01 to 0.045 mass %; in a case where strength is
necessary, more preferably 0.10 to 0.70 mass %, further more preferably
0.12 to 0.65 mass %, and most preferably 0.32 to 0.65 mass %), and
0.00005 to 0.0050 mass % of O, in which a content [Co] mass % of Co and a
content [P] mass % of P satisfy a relationship of
X1=([Co]-0.007)/([P]-0.008) where X1 is 2.9 to 6.1, preferably 3.1 to
5.6, more preferably 3.3 to 5.0, and most preferably 3.5 to 4.3, and the
remainder including Cu and inevitable impurities.

[0043] The second invention alloy has the same composition ranges of Co,
P, and Sn as those of the first invention alloy, and is an alloy
composition that further contains at least any one of 0.01 to 0.15 mass %
of Ni (preferably 0.015 to 0.13 mass %, more preferably 0.02 to 0.09 mass
%) and 0.005 to 0.07 mass % of Fe (preferably 0.008 to 0.05 mass %, more
preferably 0.012 to 0.035 mass %), in which a content [Co] mass % of Co,
a content [Ni] mass % of Ni, a content [Fe] mass % of Fe, and a content
[P] mass % of P satisfy a relationship of
X2=([Co]+0.85×[Ni]+0.75×[Fe]-0.007)/([P]-0.008) where X2 is
2.9 to 6.1, preferably 3.1 to 5.6, more preferably 3.3 to 5.0, and most
preferably 3.5 to 4.3 and a relationship of
X3=1.5×[Ni]+3×[Fe], X3 is 0.015 to [Co], preferably 0.025 to
(0.85×[Co]), and more preferably 0.04 to (0.7×[Co]), and the
remainder including Cu and inevitable impurities.

[0044] The third invention alloy is an alloy composition that further
contains, in addition to the composition of the first invention alloy or
the second invention alloy, at least any one of 0.003 to 0.5 mass % of
Zn, 0.002 to 0.2 mass % of Mg, 0.003 to 0.5 mass % of Ag, 0.002 to 0.3
mass % of Al, 0.002 to 0.2 mass % of Si, 0.002 to 0.3 mass % of Cr, and
0.001 to 0.1 mass % of Zr.

[0045] Next, a process of producing the high performance copper pipe, rod,
or wire will be described. A raw material is melted to cast a billet, and
then the billet is heated to perform a hot extruding process, thereby
producing a rod, a pipe, a buss bar, a polygonal rod, or a profile bar
having a complicated shape in the sectional view. The rod or the pipe is
additionally drawn by a drawing process to make the rod and the pipe thin
and to make the rod or the pipe into a wire by a wire drawing process (a
drawing/wire drawing process is the general term of the drawing process
of drawing the rod and the wire drawing process of drawing the wire).
Only a hot extruding process may be performed without the drawing/wire
drawing process.

[0046] A heating temperature of the billet is 840 to 960° C., and
an average cooling rate from 840° C. after the extruding or a
temperature of the extruded material to 500° C. is 15°
C/second or higher. A heat treatment TH1 at 375 to 630° C. for 0.5
to 24 hours may be performed after the hot extruding process. The heat
treatment TH1 is mainly for precipitation. The heat treatment TH1 may be
performed during the drawing/wire drawing process or after the
drawing/wire drawing process and may be performed more than one time. The
heat treatment TH1 may be performed after pressing or forging of the rod.
In addition, a heat treatment TH2 at 200 to 700° C. for 0.001
seconds to 240 minutes may be performed after the drawing/wire drawing
process. The heat treatment TH2 is firstly for restoration of ductility
and flexibility of a thin wire, a thin rod, and the like according to the
TH1 or those damaged by a high cold working process. The heat treatment
TH2 is secondly for heat treatment restoration for restoration of
conductivity damaged by the high cold working process, and may be
performed more than one time. After the heat treatment, the drawing/wire
drawing process may be performed again.

[0047] Next, the reason of adding each element will be described. Co is
satisfactorily 0.13 to 0.33 mass %, preferably 0.15 to 0.32 mass %, and
most preferably 0.16 to 0.29 mass %. High strength, high conductivity,
and the like cannot be obtained by independent addition of Co. However,
when Co is added together with P and Sn, high strength and high heat
resistance are obtained without decreasing thermal and electrical
conductivity. The independent addition of Co slightly increases the
strength, and does not cause a significant effect. When the content is
over the upper limit, the effects are saturated and the conductivity is
decreased. When the content is below the lower limit, the strength and
the heat resistance do not become high even when Co is added together
with P. In addition, the desired metal structure is not formed after the
heat treatment TH1.

[0048] P is satisfactorily 0.044 to 0.097 mass %, preferably 0.048 to
0.094 mass %, and most preferably 0.051 to 0.089 mass %. When P is added
together with Co and Sn, it is possible to obtain high strength and high
heat resistance without decreasing thermal and electrical conductivity.
The independent addition of P improves fluidity and strength and causes
grain sizes to be fine. When the content is over the upper limit, the
effects (high strength, high heat resistance) are saturated and the
thermal and electrical conductivity is decreased. In addition, cracking
easily occurs at the time of casting or extruding. In addition,
ductility, particularly, repetitive bending workability is deteriorated.
When the content is below the lower limit, the strength and the heat
resistance do not become high, and the desired metal structure is not
formed after the heat treatment TH1.

[0049] When Co and P are added together in the above-described composition
ranges, strength, heat resistance, high-temperature strength, wear
resistance, hot deformation resistance, deformability, and conductivity
become satisfactory. When either of Co and P in the composition is low in
content, a significant effect is not exhibited in any of the
above-described characteristics. When the content is too large, problems
occur such as deterioration of hot deformability, increase of hot
deformation resistance, hot process crack, bending process crack, and the
like, as in the case of the independent addition of each element. Both Co
and P are essential elements to achieve the object of the invention, and
improve strength, heat resistance, high-temperature strength, and wear
resistance without decreasing electrical and thermal conductivity under a
proper combination ratio of Co, P, and the like. As the contents of Co
and P are increased within these composition ranges, precipitates of Co
and P are increased and all theses characteristics are improved. Co:
0.13% and P: 0.044% are the minimum contents necessary for obtaining
sufficient strength, heat resistance, and the like. Both elements of Co
and P suppress recrystallized grain growth after the hot extruding, and
keep fine grains by an increasing effect with solid-solution of Sn in
matrix as described later, without regard to high temperature from the
fore end to the rear end of an extruded rod. At the time of heat
treatment, the formation of fine precipitates of Co and P significantly
contribute to both characteristics of strength and conductivity, followed
by recrystallization of matrix having high heat resistance by Sn.
However, when Co is more than 0.33% and P 0.097%, improvement of the
effects in the characteristics is not substantially recognized, and the
above-described defects rather occur.

[0050] Only with precipitates mainly based on Co and P, strength is not
enough and heat resistance of matrix is not yet sufficient, thereby
obtaining no stability. With solid solution of Sn in matrix, the alloy
becomes harder with addition of a small amount of Sn of 0.005 mass % or
higher. In addition, Sn makes grains of an extruded material hot-extruded
at a high temperature fine to suppress grain growth, and thus keeps fine
grains at a high temperature after extrusion but before forced cooling.
As described above, strength and heat resistance can be improved by solid
solution of Sn while slightly sacrificing conductivity. Sn decreases
susceptibility of Co, P, and the like to solution. In the high
temperature state of forced cooling after the extrusion, and in the
course of forced cooling for about 20° C./second, Sn retains most
of Co and P in a solid solution state. In addition, at the time of heat
treatment, Sn has an effect of dispersing the precipitates, mainly based
on Co and P, more finely and uniformly. In addition, there is an effect
on wear resistance depending on strength and hardness.

[0051] Sn is required to fall within the above-described composition range
(0.005 to 0.80 mass %). However, in a case where particularly high
strength is not necessary and high electrical and thermal conductivity
are necessary, the content is satisfactorily 0.005 to 0.095 mass %, and
most preferably 0.01 to 0.045 mass %. The particularly high electrical
conductivity means that the conductivity is higher than electrical
conductivity 65%IACS of pure aluminum. In the present case, the
particularly high electrical conductivity indicates 65%IACS or higher. In
case of laying emphasis upon strength, the content is satisfactorily 0.1
to 0.70 mass %, and more satisfactorily 0.32 to 0.65 mass %. Heat
resistance is improved by adding a small amount of Sn, thereby making
grains of a recrystallized part fine and improving strength, bending
workability, flexibility, and impact resistance.

[0052] When the content of Sn is below the lower limit (0.005 mass %),
strength, bending workability and particularly, heat resistance of matrix
deteriorate. When the content is over the upper limit (0.80 mass %),
thermal and electrical conductivity is decreased and hot deformation
resistance is increased. Accordingly, it is difficult to perform a
hot-extruding process at an high extruding ratio. In addition, heat
resistance of matrix is rather decreased. Wear resistance depends on
hardness and strength, and thus it is preferable to contain a large
amount of Sn. When a content of oxygen is over 0.0050 mass %, P and the
like are likely to combine with oxygen rather than Co and P. In addition,
there are risks of deterioration of ductility and flexibility, and
hydrogen embrittlement in high temperature heating. Accordingly, the
content of oxygen is necessarily 0.0050 mass % or less.

[0053] To obtain high strength and high conductivity as the object of the
invention, a combination ratio of Co, Ni, Fe, and P, and size and
distribution of precipitates are very important. Diameters of spherical
or oval precipitates of Co, Ni, Fe, and P such as CoxPy,
CoxNiyPx, and CoxFeyPx are 1.5 to 20 nm, or
90%, preferably at least 95% of the precipitates are 0.7 to 30 nm or 2.5
to 30 nm (30 nm or less), when defined two-dimensionally on a plane
surface as an average size of the precipitates like several nm to about
10 nm. The precipitates are uniformly precipitated, thereby obtaining
high strength. In addition, precipitates of 0.7 and 2.5 nm is the
smallest size capable of being measured with high precision, when
observed with 750,000-fold magnification or 150,000-fold magnification
using a general transmission electron microscope TEM and its dedicated
software. Accordingly, if precipitates having a diameter of less than 0.7
or less than 2.5 nm could be observed and measured, a preferable ratio of
precipitates having diameters of 0.7 to 30 nm or 2.5 to 30 nm should be
changed. The precipitates of Co, P, and the like improve high-temperature
strength at 300° C. or 400° C. required for welding tips or
the like. When exposed to a high temperature of 700° C.,
generation of recrystallized grains is suppressed by the precipitates of
Co, P, and the like or by precipitation of Co, P, and the like in the
solid solution state, thereby keeping high strength. Most of the
precipitates remain and stay fine, thereby keeping high conductivity and
high strength. Since wear resistance depends on hardness and strength,
the precipitates of Co, P, and the like are effective on wear resistance.

[0054] The contents of Co, P, Fe, and Ni have to satisfy the following
relationships. Among the content [Co] mass % of Co, the content [Ni] mass
% of Ni, the content [Fe] mass % of Fe, and the content [P] mass % of P,
as X1=([Co]-0.007)/[P]-0.008), X1 is 2.9 to 6.1, preferably 3.1 to 5.6,
more preferably 3.3 to 5.0, and most preferably 3.5 to 4.3. In case of
adding Ni and Fe, as
X2=([Co]+0.85×[Ni]+0.75×[Fe]-0.007)/([P]-0.008), X2 is 2.9 to
6.1, preferably 3.1 to 5.6, more preferably 3.3 to 5.0, and most
preferably 3.5 to 4.3. When X1 and X2 are over the upper limits, thermal
and electrical conductivity is decreased. Accordingly, heat resistance
and strength are decreased, grain growth is not suppressed, and hot
deformation resistance is increased. When X1 and X2 are below the lower
limits, thermal and electrical conductivity is decreased. Accordingly,
heat resistance is decreased, and thus hot and cold ductility is
deteriorated. Particularly, necessary high thermal and electrical
conductivity, strength, and balance with ductility deteriorate.

[0055] Even if a combination ratio of each element such as Co is the same
as a configuration ratio in a compound, not all the content is combined.
In the above-described formula, ([Co]-0.007) means that Co remains in a
solid solution state by 0.007 mass %, and ([P]-0.008) means that P
remains in a solid solution state in matrix by 0.008 mass %. That is,
when a precipitation heat treatment is performed with a precipitation
heat treatment condition and combination of Co and P that can be
industrially performed in the invention, about 0.007% of Co and about
0.008% of P do not form precipitates and remain in a solid solution state
in matrix. Accordingly, a mass ratio of Co and P has to be determined by
subtracting 0.007% and 0.008% from mass concentrations of Co and P,
respectively. The precipitates of Co and P, where a mass concentration
ratio of Co:P is substantially 4.3:1 to 3.5:1, are Co2P,
Co2.aP, Co1.bP, or the like. When fine precipitates based on
Co2P, Co2.aP, Co1.bP, or the like are not formed, high
strength and high electrical conductivity as the main subject of the
invention cannot be obtained.

[0056] That is, there is insufficiency in determination of the composition
of Co and P, or the ratio of mere Co and P, and the conditions such as
([Co]-0.007)/([P]-0.008)=2.9 to 6.1 (preferably 3.1 to 5.6, more
preferably 3.3 to 5.0, and most preferably 3.5 to 4.3) are indispensable.
When ([Co]-0.007) and ([P]-0.008) are more preferable or most preferable
ratios, desired fine precipitates are formed and thus the condition
becomes critical for a high conductivity and high strength material.
Meanwhile, when ([Co]-0.007) and ([P]-0.008) are away from the present
claims, preferable ranges, or most preferable ratios, either Co or P does
not form precipitates and becomes solid solution state. Accordingly, a
high strength material cannot be obtained and conductivity is decreased.
In addition, precipitates having undesired composition ratio are formed,
and sizes of precipitates are increased. Moreover, such precipitates do
not contribute to strength so much, and thus a high conductivity and high
strength material cannot be achieved.

[0057] Independent addition of elements of Fe and Ni does not contribute
to the improvement of characteristics such as heat resistance and
strength so much, and also decreases conductivity. However, Fe and Ni
replace a part of functions of Co under the co-addition of Co and P. In
the above-described formula ([Co]+0.85×[Ni]+0.75×[Fe]-0.007),
a coefficient 0.85 of [Ni] and a coefficient 0.75 of [Fe] represent
ratios of Ni and Fe combined with P when a combining ratio of Co and P is
1. That is, in the formula, "-0.007" and "-0.008" of
([Co]+0.85×[Ni]+0.75×[Fe]-0.007) and ([P]-0.008,
respectively, mean that not all Co and P are formed into precipitates
even when Co, Ni, Fe, and P are ideally combined and are subjected to a
precipitation heat treatment under an ideal condition. When the
precipitation heat treatment is performed under a precipitation heat
treatment condition with combination of Co, Ni, Fe, and P which can be
industrially performed in the invention, about 0.007% of
([Co]+0.85×[Ni]+0.75×[Fe]) and about 0.008% of P do not form
precipitates and remain in a solid solution state in matrix. Accordingly,
a mass ratio of Co or the like and P has to be determined by subtracting
0.007% and 0.008% from mass concentrations of
([Co]+0.85×[Ni]+0.75×[Fe]) and P, respectively. The
thus-obtained precipitates of Co or the like and P, where a mass
concentration ratio of Co:P becomes about 4.3:1 to 3.5:1, need to be
Co2P, Co2.aP, or Co1.bP mainly and also
CoxNiyFezPA, CoxNiyPz,
CoxFeyPz, and the like obtained by substituting a part of
Co with Ni and Fe. When fine precipitates, Co2P or Co2.xPy
basically, are not formed, high strength and high electrical conductivity
as the main subject cannot be obtained.

[0058] That is, there is insufficiency with determination of the
composition of Co and P, or the ratio of mere Co and P, and
([Co]+0.85×[Ni]+0.75×[Fe]-0.007)/([P]-0.008)=2.9 to 6.1
(preferably 3.1 to 5.6, more preferably 3.3 to 5.0, and most preferably
3.5 to 4.3) becomes an indispensable condition. When ([Co]-0.007) and
([P]-0.008) are more preferable or most preferable ratios, desired fine
precipitates are formed and thus the condition becomes critical for a
high conductivity and high strength material. When the condition is away
from the present claims, preferable ranges, or most preferable ratios,
either Co or the like or P does not form precipitates and becomes solid
solution state. Accordingly, a high strength material cannot be obtained
and conductivity is decreased. In addition, precipitates having undesired
composition ratio are formed, and sizes of precipitates are increased.
Moreover, such precipitates do not contribute to strength so much, and a
high conductivity and high strength material cannot be achieved.

[0059] Meanwhile, when another element is added to copper, conductivity is
decreased. For example, when any one of Co, Fe, and P is added to pure
copper by 0.02 mass %, thermal and electrical conductivity is decreased
by about 10%. However, when Ni is added by 0.02 mass %, thermal and
electrical conductivity are decreased only by about 1.5%. In the
invention alloy, when a precipitation heat treatment is performed under a
precipitation heat treatment condition, about 0.007% of C and about
0.008% of P do not form into precipitates and remain in matrix in a solid
solution state. Accordingly, the upper limit of conductivity is 89%IACS
or lower. Depending on the additive amount or the combination ratio,
conductivity becomes substantially 87%IACS or lower. However, for
example, conductivity 80%IACS is substantially the same as that of pure
copper C1220 in which P is added by 0.03%, and is higher than
conductivity 65%IACS of pure aluminum by 15%IACS, which can still be
recognized as high conductivity. Thermal conductivity of the invention
alloy is maximum 355 W/mK and is substantially 349 W/mK or lower at
20° C., from the solid solution state of Co and P, in the same
manner as conductivity.

[0060] When the values X1 and X2 of the above-described formulas of Co, P,
and the like fall out of the most preferable range, the amount of
precipitates is decreased, uniform dispersion and super-refinement of the
precipitates are deteriorated. Accordingly, excessive Co, P, or the like
comes into solid solution state in matrix without being precipitated, and
strength or heat resistance is decreased, thereby decreasing thermal and
electrical conductivity. When Co, P, and the like are appropriately
combined and fine precipitates are uniformly distributed, a significant
effect in ductility such as flexibility is exhibited by a synergetic
effect with Sn.

[0061] Fe and Ni replace a part of functions of Co, and cause to more
effectively combine Co with P. The single addition of either Fe and Ni
decreases conductivity, and thus does not contribute to improvement of
characteristics such as heat resistance and strength so much. However,
the single addition of Ni improves a stress relaxation resistance
required for connectors or the like. In addition, Ni has the function of
replacing Co under the co-addition of Co and P, and the decrease of
conductivity by Ni is small. Accordingly, Ni can minimized the decrease
of conductivity even when the value of the formula
([Co]+0.85×[Ni]+0.75×[Fe]-0.007)/([P]-0.008) falls out of the
middle value of 2.9 to 6.1. In addition, Ni has an effect of suppressing
diffusion of Sn even when a temperature during usage is increased in
Sn-coated connectors or the like. However, when Ni is excessively added
by 0.15 mass % or higher or the value of the formula
X3=1.5×[Ni]+3×[Fe] is over [Co], the composition of
precipitates is gradually changed. Accordingly, Ni does not contribute to
improvement of strength or heat resistance, and further hot deformation
resistance is increased, thereby deteriorating conductivity. In
consideration of this point, it is preferable that Ni be added by the
above-described Ni content or fall within the preferable range in the
formula of X3.

[0062] A small amount of Fe together with Co and P improves strength,
increases non-recrystallized structure, and makes the recrystallized part
fine. However, when Fe is excessively added by 0.07 mass % or higher or
the value of the formula X3=1.5×[Ni]+3×[Fe] is over [Co], the
composition of precipitates is gradually changed. Accordingly, Fe does
not contribute to improvement of strength or heat resistance, and further
hot deformation resistance is increased, thereby deteriorating
conductivity. In consideration of this point, it is preferable that Fe be
added by the above-described Fe content or fall within the preferable
range in the formula of X3.

[0063] Zn, Mg, Ag, Al, and Zr render S mixed in the course of recycle of
copper harmless, decrease intermediate temperature embrittlement, and
improve ductility and heat resistance. Zn of 0.003 to 0.5 mass %, Mg of
0.002 to 0.2 mass %, Ag of 0.003 to 0.5 mass %, Al of 0.002 to 0.3 mass
%, Si of 0.002 to 0.2 mass %, Cr of 0.002 to 0.3 mass %, Zr of 0.001 to
0.1 mass % strengthen the alloy substantially without decreasing
conductivity within the ranges thereof. Zn, Mg, Ag, and Al improve
strength of the alloy by solid solution hardening, and Zr improves
strength of the alloy by precipitation hardening. Zn improves solder
wetting property and a brazing property. Zn or the like has an effect of
promoting uniform precipitation of Co and P. Ag further improves heat
resistance. When the contents of Zn, Mg, Ag, Al, Si, Cr, and Zr are below
the lower limits of the composition ranges, the above-described effects
are not exhibited. When the contents are over the upper limits, the
above-described effects are saturated and conductivity is decreased.
Accordingly, hot deformation resistance is increased, thereby
deteriorating deformability. In addition, the content of Zn is preferably
0.045 mass % or less in consideration of an influence on a product and an
influence on a device due to vaporization of Zn, when the produced high
performance copper alloy rod, wire, a press-formed article thereof, or
the like is brazed in a vacuum melting furnace, when it is used under
vacuum, or when it is used under a high temperature. In addition, when an
extruding ratio is high at the time of extruding the pipe or rod,
addition of Cr, Zr, and Ag causes hot deformation resistance to increase,
thereby deteriorating deformability. Therefore, more preferably, the
content of Cr is 0.1 mass % or less, the content of Zr is 0.04 mass % or
less, and the content of Ag is 0.3 mass % or less.

[0064] Next, working processes will be described. A heating temperature of
a billet at hot extruding needs to be 840° C. necessary for
sufficiently solid-dissolving Co, P, and the like. When the temperature
is higher than 960° C., grains of an extruded material are
coarsened. When the temperature at the time of starting the extruding is
higher than 960° C., the temperature decreases during the
extrusion. Accordingly, a difference occurs between degrees of grains at
the extruding starting part and the extruding completing part, and thus
uniform materials cannot be obtained. When the temperature is lower than
840° C., solution (solid solution) of Co and P is insufficient,
and precipitation hardening is insufficient even when performing an
appropriate heat treatment in the after-process. The billet heating
temperature is preferably 850 to 945° C., more preferably 865 to
935° C., and most preferably 875 to 925° C. When the
content of Co+P is 0.25 mass % or less, the temperature is 870 to
910° C. When the content of Co+P is over 0.25 mass % and 0.33 mass
% or less, the temperature is 880 to 920° C. When the content of
Co+P is over 0.33 mass %, the temperature is 890 to 930° C. That
is, the optimal temperature is changed according to the content of Co+P,
even though the difference is minor. The reason is because Co and P are
sufficiently solid-dissolved at a low temperature in the above-described
temperature ranges when Co, P, the like are in an appropriate range and
the content of Co+P is small, but a temperature of solid-dissolving Co
and P is increased when the content of Co+P is increased. When the
temperature is over 960° C., the solution is saturated. In
addition, even in the invention alloy, when the temperature of the rod
during the extruding and just after the extruding is increased, grain
growth is remarkably promoted, and the grains are rapidly coarsened,
thereby deteriorating mechanical characteristics.

[0065] Considering decrease in temperature of the billet during the
extruding, the temperature of the billet corresponding to the later half
of the extruding has to be set higher than that of the leading end and
the center portion by 20 to 30° C. by induction heating of a
billet heater or the like. To prevent the temperature of extruding the
extruded material from decreasing, it is surely preferable that a
temperature of a container be high, satisfactorily 250° C. or
higher, and more preferably 300° C. or higher. Similarly, it is
preferable that a dummy block be preliminarily heated so that a
temperature of the dummy block on the rear end side of the extruding is
250° C. or higher, and preferably 300° C. or higher.

[0066] Next, cooling after the extruding will be described. The invention
alloy has very low solution sensitivity as compared with Cr--Zr copper or
the like, and thus a cooling rate higher than 100° C./second is
not particularly necessary. However, even if grain growth rapidly occurs
and the solution sensitivity is not high when materials are left under a
high temperature for a long time, it is preferable that the cooling rate
be higher than 15° C./second when considering the solution state.
In hot extruding, the extruded material is in an air cooling state until
the material reaches a forced cooling device. Naturally, it is preferable
that the time during this be shortened. Particularly, as an extruding
ratio H (sectional area of billet/total sectional area of extruding
material) is smaller, more time until reaching cooling equipment is
necessary. Accordingly, it is preferable that a moving rate of a ram,
that is, an extruding rate be raised. When a deformation rate is raised,
grains of the extruded material become small. As a diameter of the
material is larger, the cooling rate is decreased. In this specification,
"solution sensitivity is low" means that atoms solid-dissolved at a high
temperature are hardly precipitated even when a cooling rate is low
during cooling, and "solution sensitivity is high" means that atoms are
easily precipitated when the cooling rate is low.

[0067] With these factors, as extruding conditions, the moving rate of the
ram (extruding rate of billet) is 30×H-1/3 mm/second or
higher, more preferably 45×H-1/3 mm/second or higher, and most
preferably 60×H-1/3 mm/second or higher, from a relationship
with the extruding ratio H. In a cooling rate of an extruding material
for easily diffusing atoms, an average cooling rate from a temperature of
a material just after the extruding or 840° C. to 500° C.
is 15° C./second or higher, preferably 22° C./second or
higher, and more preferably 30° C./second or higher, and it is
necessary to satisfy any one of the conditions.

[0068] When the extruding rate is increased, a generating site of
recrystallization nucleus is expanded to cause grains to be fine at hot
extruding completion. In this specification, the hot extruding completion
refers to a state where cooling after the hot extruding is completed. In
addition, when an air cooling state up to a cooling device is shortened,
rather more Co and P are solid-dissolved, and it is possible to suppress
grain growth. Accordingly, it is preferable that a distance from the
extruding equipment to the cooling device be short, and a cooling method
be a method with a high cooling rate such as water cooling.

[0069] As described above, when the cooling rate after the extruding is
raised, a grain size at the hot extruding completion can be small. The
grain size is satisfactorily 5 to 75 μm, preferably 7.5 to 65 μm,
and more preferably 8 to 55 μm. Generally, as the grain size is
smaller, a mechanical characteristic at a normal temperature becomes more
satisfactory. However, when the grain size is too small, heat resistance
or a high-temperature characteristic is deteriorated. Accordingly, it is
preferable that the grain size be 8 μm or more. When the grain size is
over 75 μm, sufficient strength cannot be obtained and fatigue
(repetitive bending) strength is decreased. Accordingly, ductility is
insufficient, and a surface roughness occurs when performing a bending
process or the like. The optimal producing condition is that the
extruding is performed at the optimal temperature, the extruding rate is
increased (the billet extruding rate is 30×H-1/3 mm/second or
higher) to break a structure of casting, the generating site of the
recrystallization nucleus is expanded, and the air cooling time is
shortened to suppress the grain growth. The cooling is rapid cooling such
as water cooling. Since the grain size is largely affected by the
extruding ratio H, the grain size becomes smaller as the extruding ratio
H becomes higher.

[0070] Next, the heat treatment TH1 will be described. A basic condition
of the heat treatment TH1 is at 375 to 630° C. for 0.5 to 24
hours. As the processing rate of the cold working process after the hot
extruding becomes higher, a precipitation site of compounds of Co, P, and
the like is increased, and Co, P, and the like are precipitated at a low
temperature, thereby increasing strength. When the cold working
processing rate is 0%, the condition is at 450 to 630° C. for 0.5
to 24 hours, and preferably at 475 to 550° C. for 2 to 12 hours.
In addition, to obtain higher conductivity, for example, a two-step heat
treatment at 525° C. for 2 hours and at 500° C. for 2 hours
is effective. When the processing rate before the heat treatment is
increased, the precipitation site is increased. Accordingly, in case of a
processing rate of 10 to 50%, the optimal heat treatment condition is
changed toward a low temperature of 10 to 20° C. A preferable
condition is at 420 to 600° C. for 1 to 16 hours, and more
preferably at 450 to 530° C. for 2 to 12 hours.

[0071] In addition, a temperature, a time, and a processing rate are more
clarified. As a temperature T (° C.), a time (hour), and a
processing rate RE (%), when a value of
(T-100×t-1/2-50×Log((100-RE)/100)) is a heat treatment
index TI, 400≦TI≦540 is satisfactory, preferably
420≦TI≦520, and most preferably 430≦TI≦510.
In this case, Log is natural logarithm. For example, when the heat
treatment time is extended, the temperature is changed toward a low
temperature, but an influence on the temperature is substantially given
as a reciprocal of a square root of a time. In addition, as the
processing rate is increased, the precipitation site is increased and
movement of atoms is increased, and thus it is easy to perform
precipitation. Accordingly, the optimal heat treatment temperature is
changed toward a low temperature. Herein, the process ratio RE is
(1-(sectional area of pipe, rod, or wire after process)/(sectional area
of pipe, rod, or wire before process))×100%. When the cold working
process and the heat treatment TH1 are performed more than one time, a
total cold working processing rate from the extruded material is applied
to RE.

[0072] When the heat treatment TH1 is performed during the drawing/wire
drawing process, it is preferable that the processing rate until the heat
treatment TH1 after the extruding be over the processing rate after the
heat treatment TH1 to have higher conductivity and ductility.
Precipitation heat treatment may be performed more than one time. In such
a case, it is preferable that the total cold working processing rate
until the final precipitation heat treatment be over the processing rate
after the heat treatment TH1. The cold working process after the
extruding causes atoms of Co, P, and the like to move easily in the heat
treatment TH1, thereby promoting precipitation of Co, P, and the like. As
the processing rate becomes higher, the precipitation is performed by a
low-temperature heat treatment. In the cold working process after the
heat treatment TH1, strength is improved by process hardening, but
ductility is decreased. In addition, conductivity is significantly
decreased. Considering the overall balance of conductivity, ductility,
and strength, it is preferable that the processing rate after the heat
treatment TH1 be lower than the processing rate before the heat
treatment. When an intensive process at the total cold working processing
rate higher than 90% until the final wire is performed after the
extruding, ductility is insufficient. Considering ductility, the
following more preferable precipitation heat treatment is necessary.

[0073] That is, fine grains with low dislocation density or recrystallized
grains are generated in a metal structure of matrix, thereby restoring
ductility of the matrix. In the specification, both the fine grains and
the recrystallized grains are referred to as recrystallized grains. When
grain sizes thereof are large, or when a ratio occupied by them is high,
the matrix becomes too soft. In addition, the precipitates are grown to
increase the average grain diameter of the precipitates, and strength of
the final wire is decreased. Accordingly, the ratio occupied by the
recrystallized grains of the matrix at the time of the precipitation heat
treatment is 45% or lower, preferably 0.3 to 30%, and more preferably 0.5
to 15% (the remainder is non-recrystallized structure), and the average
grain size of the recrystallized grains is 0.7 to 7 μm, preferably 0.7
to 5 μm, and more preferably 0.7 to 4 μm.

[0074] The above-described fine grains are too small, and thus it may be
difficult to distinguish the grains from the rolling structure by a metal
microscope. However, using EBSP (Electron Back Scattering diffraction
Pattern), it is possible to observe the fine grains with a little
deformation at a low dislocation density due to a random direction
centered on an original grain boundary extending mainly in the rolling
direction. In the invention alloy, the fine grains or the recrystallized
grains are generated by the cold working process at a processing rate of
75% or higher and the precipitation heat treatment. Ductility of the
process-hardened material is improved by the fine recrystallized grains
without decreasing strength. Also in case of a press product and a
cold-forged product, the heat treatment TH1 may be put in the step of a
rod, and the heat treatment may be put in after pressing and forging.
Finally, over 630° C. or the temperature condition of the heat
treatment TH1, for example, in case of performing a brazing process, the
heat treatment TH1 may be unnecessary. In the heat treatment condition,
the total cold working processing rate from the extruded material is
applied to RE similarly in both cases of performing the heat treatment
and performing no heat treatment at the step of a rod.

[0075] In a two-dimensional observing plane, substantially circular or
substantially oval fine precipitates, which have an average grain size of
1.5 to 20 nm or in which at least 90% of the precipitates are 0.7 to 30
nm or 2.5 to 30 nm (30 nm or less), are uniformly dispersed and obtained
by the heat treatment TH1. The precipitates are uniformly and finely
distributed and become the same size. As the diameter of the precipitates
become smaller, the sizes of the recrystallized grains become smaller,
thereby improving strength and heat resistance. The average grain
diameter of the precipitates is satisfactorily 1.5 to 20 nm, and
preferably 1.7 to 9.5 nm. When the heat treatment TH1 is performed once,
or when the cold working processing rate before the heat treatment TH1 is
as low as 0 to 50%, particularly, in case of both processes, strength
depends mainly on precipitation hardening, and the precipitates have to
be fine, with most preferable size of 2.0 to 4.0 nm.

[0076] When the total cold working processing rate is 50% or higher, or is
75% or higher, ductility becomes insufficient. Accordingly, matrix has to
have ductility at the time of the heat treatment TH1. As a result, it is
preferable that the precipitates be most preferably 2.5 to 9 nm, and
ductility and conductivity be improved and balanced by sacrificing a
little precipitation hardening. A ratio of the precipitates of 30 nm or
less is satisfactorily 90% or higher, preferably 95% or higher, and most
preferably 98% or higher. In the observation using the TEM (transmission
electron microscope), there are various kinds of dislocation in the cold
working processed materials, and thus it is difficult to accurately
measure sizes of the precipitates. Accordingly, after the extruding,
materials subjected to the precipitation heat treatment without the cold
working process, or samples in which recrystallized grains or fine grains
are generated at the time of the precipitation heat treatment were used.
Even when the precipitates were basically subjected to the cold working
process, there was not great variation in grain sizes, and the
precipitates were not substantially grown under the final restoration
heat treatment condition. In 150,000-fold magnification, it was possible
to recognize the precipitates up to a diameter of 1 nm, but the
precipitates were measured also in 750,000-fold magnification because it
was considered that there was a problem in size precision of fine grains
of 1 to 2.5 nm.

[0077] In the measurement of 150,000-fold magnification, precipitates
having diameters smaller than 2.5 nm were excluded (they were not
included in calculation) from the precipitates, considering that there
was a large margin of error. Also in the measurement of 750,000-fold
magnification, precipitates having diameters smaller than 0.7 nm were
excluded (not recognized) from the precipitates, because of a large
margin of error. Centered on the precipitates having an average grain
diameter of about 8 nm, it is considered that precision of measurement in
750,000-fold magnification for precipitates smaller than about 8 nm is
satisfactory. Accordingly, a ratio of the precipitates of 30 nm or less
indicates accurately 0.7 to 30 nm or 2.5 to 30 nm. The sizes of the
precipitates of Co, P, and the like have an influence on strength,
high-temperature strength, formation of non-recrystallized structure,
fineness of recrystallization structure, and ductility. In addition,
naturally, the precipitates do not include crystallized materials created
in the casting step.

[0078] Daring to define uniform dispersion of precipitates, when the
precipitates were observed using the TEM in 150,000-fold magnification or
750,000-fold magnification, a distance between the most adjacent
precipitates of at least 90% of precipitates in any area of 1000
nm×1000 nm at a microscope observing position described later
(except for particular parts such as the outermost surface) is defined as
150 nm or less, preferably 100 nm or less, and most preferably within 15
times of the average grains size. In any area of 1000 nm×1000 nm at
the microscope observing position to be described later, it can be
defined that there are at least 25 precipitates or more, preferably 50 or
more, most preferably 100 or more, that is, there is no large
non-precipitated zone having an influence on characteristics even when
taking any micro-part in a standard region, that is, there is no presence
of non-uniform precipitated zone.

[0079] Next, the heat treatment TH2 will be described. When a high cold
working processing rate is given after the precipitation heat treatment
like a thin wire, the heat treatment TH2 is performed on a hot-extruded
material according to the invention alloy at a temperature equal to or
lower than a recrystallization temperature, in the course of a wire
drawing process to improve ductility, and then strength is improved when
performing the wire drawing process. In addition, when the heat treatment
TH2 is performed after the wire drawing process, strength is slightly
decreased but ductility such as flexibility is significantly improved.
After the heat treatment TH1, when the cold working processing rate is
over 30% or 50%, the precipitates of Co, P, and the like become fine in
addition to increase of dislocation density caused by the cold working
process. Accordingly, electrical conductivity is decreased, and
conductivity is decreased by 2%IACS or higher, or 3%IACS or higher. As
the processing rate becomes higher, the conductivity is further
decreased. In case of the cold working processing rate of 90% or higher,
the conductivity is decreased by 4%IACS to 10%IACS. The degree of
decrease in conductivity is as large as twice to five times as compared
with copper, Cu--Zn alloy, Cu--Sn alloy, and the like. Accordingly, the
effect of the TH2 on conductivity is large when the high processing rate
is given. In addition, to obtain higher conductivity and higher
ductility, it is preferable to perform the heat treatment TH1.

[0080] When a wire diameter is 3 mm or less, it is preferable to carry out
a heat treatment at 350 to 700° C. for 0.001 seconds to several
seconds by continuous annealing equipment in the viewpoint of
productivity and a winding behavior at the annealing time. When laying
emphasis upon ductility, flexibility, or conductivity at the final cold
working processing rate of 60% or higher, it is preferable to extend time
and keep at 200° C. to 375° C. for 10 minutes to 240
minutes. In addition, when there is a problem in a remaining stress, the
heat treatment TH2 may be performed as stress removing annealing or
restoration of ductility and conductivity, at the end, in the same manner
as the wire, in a rod and a cold pressing material. Conductivity or
ductility is improved by the heat treatment TH2. In a rod, a press
product, or the like, a temperature of a material is not increased for a
short time, and thus it is preferably kept at 250° C. to
550° C. for 1 minute to 240 minutes.

[0081] Characteristic of the high performance copper pipe, rod, or wire
according to the embodiment will be described. Generally, for obtaining a
high performance copper pipe, rod, or wire, there are several means such
as structure control mainly based on grain fineness, solid solution
hardening, and aging and precipitation hardening. For the aforesaid
structure control, various elements are added. However, for conductivity,
when the added elements are solid-dissolved in matrix, conductivity is
generally decreased, and conductivity is significantly decreased
according to elements. Co, P, and Fe of the invention alloy are elements
significantly decreasing conductivity. For example, only with single
addition of Co, Fe, and P to pure copper by 0.02 mass %, conductivity is
decreased by about 10%. Even in the known aging precipitation alloy, it
is impossible to efficiently precipitate added elements completely
without solid solution remaining in matrix, and conductivity is decreased
by the solid-dissolved elements. In the invention alloy, a peculiar merit
is that most of solid-dissolved Co, P, and the like can be precipitated
in the later heat treatment when Co, P, and the like as the constituent
elements are added according to the above-described formulas, thereby
securing high conductivity.

[0082] A large amount of Ni, Si, or Ti remains in matrix in titanium
copper or Corson alloy (addition of Ni and Si) known as aging hardening
copper alloy in addition to Cr--Zr copper as compared with the invention
alloy, even when a complete solution-aging process is performed on
titanium copper or Corson alloy. As a result, there is a defect that
strength is increased while conductivity is decreased. Generally, when a
solution treatment (e.g., heating at a typical solution temperature 800
to 950° C. for several minutes or more) at a high temperature
necessary for a complete solution-aging precipitation process is
performed, rains are coarsened. The coarsening of the grains has a
negative influence on various mechanical characteristics. In addition,
the solution treatment is restricted in quantity during production, and
thus the production costs drastically increase.

[0083] In the invention, it was found that a sufficient solution treatment
is performed during the hot extruding process by combination of the
composition of the invention alloy and the hot extruding process, that
structure control of grain fineness is performed, and that Co, P, and the
like are finely precipitated in the heat treatment process thereafter.

[0084] Hot extruding includes two kinds of extruding methods such as
indirect extruding (extruding backward) and direct extruding (extruding
forward). A diameter of a general billet (ingot) is 150 to 400 mm and a
length is about 400 to 2000 mm. A container of an extruder is loaded with
a billet, the container and the billet come into contact with each other,
and thus a temperature of the billet is decreased. In addition, a die to
extrude material into a predetermined size is provided at the front of
the container, and there is a steel block called dummy block at the rear,
consequently, the billet is further deprived of its heat. The time of
extruding completion is different according to a length of the billet and
an extruding size, and a time of about 20 to 200 seconds is necessary to
complete the extruding. Meanwhile, the temperature of the billet is
decreased, and the temperature of the billet is significantly decreased
after the billet is extruded until a length of the remaining billet
becomes 250 mm or less, and particularly 125 mm or less, or until the
length becomes equivalent to the diameter, particularly the radius of the
billet.

[0085] For solution, after the extruding, it is preferable to perform
immediately rapid cooling, for example, water cooling in a water tank,
shower water cooling, and forced air cooling. However, in most cases in
terms of the equipment, the extruded material is required to be coiled,
and the extruded material needs time of several seconds to ten several
seconds, until the extruded material reaches the cooling equipment
(cooling while being coiled, water cooling). That is, the extruded
material is in an air cooling state with a low cooling rate for about 10
seconds until the rapid cooling just after the extruding. As described
above, it is naturally preferable that the extruding be performed in the
state with no decrease of the temperature and that the cooling after the
extruding be rapid. However, the invention alloy has a characteristic
that the precipitation rate of Co, P, and the like is low, and thus
solution sufficiently occurs within the range of the general extruding
condition. The distance from the position where the extruding is finished
to the cooling equipment is preferably about 10 m or less.

[0086] In the high performance copper pipe, rod, or wire according to the
embodiment, Co, P, and the like are solid-dissolved in the course of the
hot extruding process to form fine recrystallized grains by combination
of the composition of Co, P, and the like and the hot extruding process.
When the heat treatment is performed after the hot extruding process, Co,
P, and the like are finely precipitated, thereby obtaining high strength
and high conductivity. When a drawing/wire drawing process is added
before and after the heat treatment, it is possible to obtain further
higher strength without decreasing conductivity, by the process
hardening. In addition, when the appropriate heat treatment TH1 is
performed, it is possible to obtain high conductivity and high ductility.
When a low-temperature annealing process (annealer annealing) is added in
the middle or at the end of the process of a wire, atoms are rearranged
by restoration or a kind of softening phenomenon, and it is possible to
obtain further higher conductivity and ductility. Nevertheless, when
strength is not sufficient yet, it is possible to improve strength by
increasing the content of Sn, or adding (solid solution hardening) Zn,
Ag, Al, Si, Cr, or Mg, depending on the balance with conductivity. The
addition of a small amount of Sn, Zn, Ag, Al, Si, Cr, or Mg does not have
a significantly negative influence on conductivity, and the addition of a
small amount of Zn has an effect of increasing ductility similarly to Sn.
The addition of Sn and Ag delays recrystallization, increases heat
resistance, and causes the recrystallized part to be refined.

[0087] Generally, aging precipitation copper alloy is completely made into
solution, and then a process of precipitation is performed, thereby
obtaining high strength and high conductivity. Performance of a material
made by the same process as the embodiment in which solution is
simplified generally deteriorates. However, performance of the pipe, rod,
or wire according to the embodiment is equivalent to or higher than that
of materials produced by the complete solution-precipitation hardening
process at a high cost. Rather, the most significant characteristic is
that excellent strength, ductility, and conductivity can be obtained in a
balanced state. The pipe, rod, or wire is produced by the hot extruding,
and thus a production cost is low.

[0088] Among practical alloys, there is only Cr--Zr copper alloy that is
high strength and high conductivity copper and solution-aging
precipitation alloy. However, hot deformability of Cr--Zr copper at
960° C. or higher is insufficient, and thus the upper temperature
limit of solution is largely restricted. The solubility limit of Cr and
Zr is rapidly decreased with slight decrease of temperature, and thus the
lower temperature limit of solid solution is also restricted.
Accordingly, a range of the temperature condition of solution is narrow.
Even if Cr--Zr copper is in a solution state at the beginning of
extruding, it cannot be sufficiently made into solution by decrease of
temperature in the middle period and the later period of extruding. In
addition, since sensitivity of a cooling rate is high, sufficient
solution cannot be performed in a general extruding process. For this
reason, even when the extruded material is subjected to an aging process,
desired properties cannot be obtained. Further, difference in properties
of strength and conductivity depending on a part of extruded material is
large, and Cr--Zr copper cannot be used as an industrial material. In
addition, Cr--Zr copper includes a large amount of active Zr and Cr, and
thus there is limitation on melting and casting. As a result, in the
producing process according to the embodiment, it cannot be produced, the
material is produced by a hot extruding method, and it is necessary to
take strict batch processes for solution-aging precipitation about
temperature management at a high temperature, which needs a high cost.

[0089] In the embodiment, it is possible to obtain a high performance
copper pipe, rod, or wire having high conductivity, strength, and
ductility in an excellent balance. In this specification, as an indicator
for evaluation in the combination of strength, elongation, and
conductivity of the pipe, rod, or wire, a performance index I is defined
as follows. When conductivity is R (%IACS), tensile strength is S
(N/mm2) and elongation is L (%), the performance index
I=R1/2×S×(100+L)/100. Under the condition that
conductivity is 45%IACS or higher, it is preferable that the performance
index I be 4300 or more. Since there is a close correlation between
thermal conductivity and electrical conductivity, the performance index I
also indicates highness or lowness of thermal conductivity.

[0090] As a more preferable condition, in a rod, on the assumption that
conductivity is 45%IACS or higher, the performance index I is
satisfactorily 4600 or more, preferably 4800 or more, and most preferably
5000 or more. Conductivity is preferably 50%IACS or higher, and more
preferably 60%IACS or higher. In case of needing high conductivity,
conductivity is satisfactorily 65%IACS or higher, preferably 70%IACS or
higher, and more preferably 75%IACS or higher. Elongation is preferably
10% or more, and more preferably 20% or more, since cold pressing,
forging, rolling, caulking, and the like may be performed.

[0091] As a more preferable condition, in a pipe or wire, on the
assumption that conductivity is 45%IACS or higher, the performance index
I is satisfactorily 4600 or more, preferably 4900 or more, more
preferably 5100 or more, and most preferably 5400 or more. Conductivity
is preferably 50%IACS or higher, and more preferably 60%IACS or higher.
In case of needing high conductivity, conductivity is preferably 65%IACS
or higher, more preferably 70%IACS or higher, and most preferably 75%IACS
or higher. In addition, when the wire needs to have a bending property or
ductility, it is preferable that the performance index I be 4300 or more,
and elongation is 5% or more. In the embodiment, a rod having a
performance index I of 4300 or more and elongation of 10% or more, and a
pipe or wire having a performance index I of 4600 or more were obtained.
It is possible to reduce a cost by reducing a diameter of the pipe, rod,
or wire. Particularly, for high conductivity, on the assumption that
conductivity is 65%IACS or higher, conductivity is preferably 70%IACS or
higher, and most preferably 75%IACS, and the performance index I is
satisfactorily 4300 or more, preferably 4600 or more, and more preferably
4900 or more. In the embodiment, a pipe, rod, or wire having conductivity
of 65%IACS or higher and a performance index I of 4300 or more were
obtained as described later. The pipe, rod, or wire has conductivity
higher than that of pure aluminum, and has high strength. Accordingly, it
is possible to reduce a cost by reducing a diameter of the pipe, rod, or
wire in a member where high current flows.

[0092] In the pipe, rod, or wire produced by extruding, it is preferable
that variation (hereinafter, the variation is referred to as variation in
extruding production lot) of conductivity and mechanical properties in a
lengthwise direction of the pipe, rod, or wire extruded from one and the
same billet be small. In the variation in extruding production lot, a
ratio of (minimum tensile strength/maximum tensile strength) of the pipe,
rod, or wire after the final process or of a material after heat
treatment is satisfactorily 0.9 or more. In conductivity, a ratio of
(minimum conductivity/maximum conductivity) is satisfactorily 0.9 or
more. Each of the ratio of (minimum tensile strength/maximum tensile
strength) and the ratio of (minimum conductivity/maximum conductivity)
are preferably 0.925 or more, and more preferably 0.95 or more. In the
embodiment, it is possible to raise the ratio of (minimum tensile
strength/maximum tensile strength) and the ratio of (minimum
conductivity/maximum conductivity), thereby improving quality. When
Cr--Zr copper having high solution sensitivity is produced by the
producing process according to the embodiment, the ratio of (minimum
tensile strength/maximum tensile strength) is 0.7 to 0.8, and variation
is large. In addition, generally, in most popular copper alloy C3604
(60Cu-37Zn-3Pb) produced by hot extruding of copper alloy, for example,
at a leading end and a trailing end of extruding, a strength ratio
thereof is normally about 0.9 by an extruding temperature difference,
metal flow of extruding, and the like. In addition, pure copper: tough
pitch copper C1100, which is not subjected to precipitation hardening,
also has a value close to 0.9 by a grain size difference. In addition, a
temperature of a leading end (head) portion just after the extruding is
generally higher than a temperature of trailing end (tail) portion by 30
to 180° C.

[0093] For high temperature usage, a welding tip or the like is required
to have high strength at 300° C. or 400° C. When strength
at 400° C. is 200 N/mm2 or higher, there is no problem in
practice. However, to obtain high-temperature strength and long life, the
strength is preferably 220 N/mm2 or higher, more preferably 240
N/mm2 or higher, and most preferably 260 N/mm2 or higher. The
high performance copper pipe, rod, or wire according to the embodiment
has strength of 200 N /mm2 or higher at 400° C., and thus it
can be used in a high temperature state. Most of precipitates of Co, P,
and the like are not solid-dissolved again at 400° C. for several
hours, and most of diameters thereof are not changed. Since Sn is
solid-dissolved in matrix, movement of atoms becomes inactive.
Accordingly, even when the pipe, rod, or wire is heated to 400°
C., recrystallized grains are not generated in a state where diffusion of
atoms is not active yet. In addition, when deformation is applied
thereto, the pipe, rod, or wire exhibits resistance against deformation
by the precipitates of Co, P, and the like. When the grain size is 5 to
75 μm, it is possible to obtain satisfactory ductility. The grain size
is preferably 7.5 to 65 μm, and most preferably 8 to 55 μm.

[0094] For high temperature usage, compositions and processes are
determined by balance of high-temperature strength, wear resistance
(substantially in proportion to strength), and conductivity required on
the assumption of high strength and high conductivity. Particularly, to
obtain strength, the cold drawing is applied before and/or after the heat
treatment. As the total cold working processing rate becomes higher, a
higher strength material is obtained. However, balance with ductility is
important. To secure elongation of 10% or more, it is preferable that the
total drawing processing rate be 60% or lower or the drawing processing
rate after the heat treatment be 30% or lower. A trolley line and a
welding tip are consumables, but it is possible to extend the life
thereof by using the invention. The high performance copper pipe, rod, or
wire according to the embodiment is very suitable for trolley lines,
welding tips, electrodes, and the like.

[0095] The high performance copper pipe, rod, or wire according to the
embodiment has high heat resistance, and Vickers hardness (HV) after
heating at 700° C. for 120 seconds is 90 or higher, or at least
80% of the value of Vickers hardness before the heating. In addition, an
average grain diameter of the precipitates in a metal structure after the
heating is 1.5 to 20 nm, at least 90% of the total precipitates is 30 nm
or less, or recrystallization ratio in the metal structure are 45% or
lower. A more preferable condition is that the average grain size is 3 to
15 nm, at least 95% of the total precipitates are 30 nm or lower, or 30%
or lower of a recrystallization ratio in a metal structure. In case of
exposure to a high temperature of 700° C., precipitates of about 3
nm become large. However, they do not substantially disappear and exist
as fine precipitates of 20 nm or less. Accordingly, it is possible to
keep high strength and high conductivity by preventing recrystallization.
As for a casting product, a cold pressing product, and a pipe, rod, or
wire which are not subjected to the heat treatment TH1, Co, P, and the
like in a solid solution state are finely precipitated once during the
heating at 700° C., and the precipitates are grown with lapse of
time. However, the precipitates do not substantially disappear and exist
as fine precipitates of 20 nm or less. Accordingly, it is possible to
obtain the same high strength and high conductivity as those of the rod
or the like which is subjected to the heat treatment TH1. Therefore, it
is possible to use it in circumstance exposed to a high temperature,
thereby obtaining high strength even after brazing used for bonding. A
brazing material is, for example, silver brazing BAg-7(40 to 60% of Ag,
20 to 30% of Cu, 15 to 30% of Zn, 2 to 6% of Sn) described in JIS Z 3261,
and a solidus temperature is 600 to 650° C. and a liquidus
temperature is 640 to 700° C. For example, in a railroad motor, a
rotor bar or an end ring is assembled by brazing. However, since these
members have high strength and high conductivity even after the brazing,
the members can endure high-speed rotation of the motor.

[0096] The high performance copper pipe, rod, or wire according to the
embodiment has excellent flexibility, and thus is suitable for a wire
harness, a connector line, a robot wire, an airplane wire, and the like.
In balance of electrical characteristics, strength, and ductility, usage
is divided into two ways that conductivity is to be 50%IACS or higher for
high strength or that conductivity is to be 65%IACS or higher, preferably
70%IACS or higher, or most preferably 75%IACS or higher although strength
is slightly decreased. Compositions and processing conditions can be
determined according to the usage.

[0097] The high performance copper pipe, rod, or wire according to the
embodiment is most suitable for electrical usage such as a power
distribution component, a terminal, or a relay produced by forging or
pressing. Hereinafter, a compression process is the general term of
forging, pressing, and the like. With high strength and ductility, the
high performance copper pipe, rod, or wire according to the embodiment is
of utility value for metal fittings of faucets or nuts, due to no concern
of stress corrosion cracking. It is preferable to use a high strength and
high conductivity material, which is subjected to a heat treatment and a
cold drawing at the step of a material, even depending on a product shape
(complexity, deformation) and ability of a press or the like. The cold
drawing processing rate of a material is appropriately determined by
ability of a press and a product shape. When a compression process with
low press ability or a very high processing rate is loaded, the drawing
is fixed with a processing rate of, for example, about 20%, without a
heat treatment after the hot extruding.

[0098] Since the material after the drawing is soft, the material can be
formed into complicated shapes in cold by the compressing process, and a
heat treatment is performed after the forming. In low-power processing
equipment, strength of a material before the heat treatment is low, and
formability is good. Accordingly, it is possible to easily perform the
forming. When the heat treatment is performed after the cold forging or
pressing, conductivity becomes high. Therefore, high-power equipment is
not necessary, and a cost is reduced. In addition, when a brazing process
is performed at a temperature higher than the temperature of the heat
treatment TH1, for example, at 700° C., after the forging or press
forming, it is not necessary to perform the heat treatment TH1,
particularly, in a pipe, rod, or wire of a material. Since Co and P in a
solution state are precipitated to increase heat resistance of matrix by
solid solution of Sn, generation of recrystallized grains in matrix is
delayed, thereby increasing conductivity.

[0099] The heat treatment condition after the compression process is
preferably a low temperature as compared with the heat treatment
condition performed after the hot extruding, before, after, or during the
drawing/wire drawing process. The reason is because when a cold working
process with a high processing rate is locally performed in the
compression process, the heat treatment is performed on the basis of the
cold working processed part. Accordingly, when the processing rate is
high, the heat treatment condition is changed toward a low temperature
side. A preferable condition is at 380 to 630° C. for 15 to 240
minutes. In the relational formula of the condition of the heat treatment
TH1, the total processing rate from the hot extruding material to the
compression processing material is applied to RE. That is, assuming that
the value of the relational formula
(T-100×t-1/2-50×Log((100-RE)/100)) is a heat treatment
index TI, the index TI is satisfactorily 400≦TI≦540,
preferably 420≦TI≦520, and most preferably
430≦TI≦510. When the heat treatment is performed on a rod
of a material, the heat treatment is not necessarily required. However,
the heat treatment is performed mainly for restoration, improvement of
conductivity, and removal of remaining stress. In that case, a preferable
condition is at 300 to 550° C. for 5 to 180 minutes.

EXAMPLE

[0100] A high performance copper pipe, rod, or wire was produced using the
above-described first invention alloy, second invention alloy, third
invention alloy, and comparative copper alloy. Table 1 shows compositions
of alloys used to produce the high performance copper pipe, rod, or wire.

[0101] A high performance copper pipe, rod, or wire was produced by a
plurality of processes using any alloy of Alloy No. 11 to 13 of the first
invention alloy, Alloy No. 21 to 24 of the second invention alloy, Alloy
No. 31 to 36 and 371 to 375 of the third invention alloy, Alloy No. 41 to
49 having a composition similar to the invention alloy as comparative
alloy, Alloy No. 51 of tough pitch copper C1100, and Alloy No. 52 of
conventional Cr--Zr copper.

[0102] FIG. 1 to FIG. 9 show flows of producing processes of the high
performance pipe, rod, or wire, and Table 2 and Table 3 show conditions
of the producing processes.

[0103] FIG. 1 shows a configuration of a producing process K. In the
producing process K, a raw material was melted by an electric furnace of
a real operation, a composition was adjusted, and thus a billet having an
outer diameter of 240 mm and a length of 700 mm was produced. The billet
was heated at 900° C. for 2 minutes, and a rod having an outer
diameter of 25 mm was extruded by an indirect extruder. Extruding ability
of the indirect extruder was 2750 tons (in the following processes, the
extruding ability is the same in the indirect extruder). A temperature of
a container of the extruder was 400° C., a temperature of a dummy
block was 350° C., and a preheated dummy block was used. In the
embodiment including the following processes, a temperature of a
container and a temperature of a dummy block were the same. An extruding
rate (moving speed of ram) was 12 mm/second, and cooling was performed by
water cooling in a coil winder away from extruding dies by about 10 m
(hereinafter, a series of processes from the melting hereto is referred
to as a process K0). A temperature of the extruded material was measured
at a part away from the extruding dies by about 3 m. As a result, a
material temperature of an extruding leading end (head) portion was
870° C., a temperature of an extruding middle portion was
840° C., and a temperature of an extruding trailing end (tail)
portion was 780° C. The leading end and trailing end portions are
positions away from the most leading end and the latest end by 3 m. As
described above, a large difference in temperature of 90° C.
occurred between the leading end and the trailing end of extruding. An
average cooling rate from 840° C. to 500° C. after the hot
extruding was about 30° C./second. Thereafter, drawing is
performed to be an outer diameter of 22 mm (process K01), a heat
treatment TH1 at 500° C. for 4 hours was performed (process K1),
and then drawing was performed to be an outer diameter of 20 mm (process
K2) by a cold drawing process. After the process K0, a heat treatment TH1
at 520° C. for 4 hours was performed (process K3), and then
drawing was performed to be an outer diameter of 22 mm (process K4). In
addition, after the process K0, a heat treatment TH1 at 500° C.
for 12 hours was performed (process K5). In C1100, a heat treatment at
150° C. for 2 hours was performed in the process K1, but there was
no precipitated element. Accordingly, a heat treatment TH1 was not
performed (the same will be applied to other producing processes
described later).

[0104] FIG. 2 shows a configuration of a producing process L. In the
producing process L, a heating temperature of the billet is different
from that of the producing process K1. The heating temperature was
825° C. in a process L1, 860° C. in a process L2,
925° C. in a process L3, and 975° C. in a process L4.

[0105] FIG. 3 shows a configuration of a producing process M. In the
producing process M, a temperature condition of the heat treatment TH1 is
different from that of the producing process K1. The temperature
condition was at 360° C. for 15 hours in a process M1, at
400° C. for 4 hours in a process M2, at 475° C. for 12
hours in a process M3, at 590° C. for 4 hours in a process M4, at
620° C. for 0.3 hours in a process M5, and at 650° C. for
0.8 hours in a process M6.

[0106] FIG. 4 shows a configuration of a producing process N. In the
producing process N, a hot extruding condition and a condition of the
heat treatment TH1 are different from those of the producing process K1.
In a process N1, a billet was heated at 900° C. for 2 minutes, and
a rod having an outer diameter of 35 mm was extruded by the indirect
extruder. An extruding rate was 16 mm/second, and cooling was performed
by water cooling. A cooling rate was about 21° C./second.
Thereafter, drawing was performed to be an outer diameter of 31 mm by a
cold drawing process, a heat treatment TH1 at 500° C. for 2 hours
and subsequently at 480° C. for 4 hours was performed. In
addition, after the water cooling in the process N1, a heat treatment TH1
at 515° C. for 2 hours and subsequently at 500° C. for 6
hours was performed (process N11). In a process N2, a billet was heated
at 900° C. for 2 minutes, and a rod having an outer diameter of 35
mm was extruded by the direct extruder. Extruding ability of the direct
extruder was 3000 tons (in the following processes, the extruding ability
is the same in the direct extruder). An extruding rate was 18 mm/second,
and cooling was performed by shower water cooling. A cooling rate was
about 17° C./second. Thereafter, drawing was performed to be an
outer diameter of 31 mm by a cold drawing process, and a heat treatment
TH1 at 500° C. for 2 hours and subsequently at 480° C. for
4 hours was performed. After the water cooling in the process N2, a heat
treatment TH1 at 515° C. for 2 hours and subsequently at
500° C. for 6 hours was performed (process N21). In a process N3,
a billet was heated at 900° C. for 2 minutes, and a rod having an
outer diameter of 17 mm was extruded by the indirect extruder. An
extruding rate was 10 mm/second, and cooling was performed by water
cooling. A cooling rate was about 40° C./second. Thereafter,
drawing was performed to be an outer diameter of 14.5 mm by a cold
drawing process, and a heat treatment TH1 at 500° C. for 4 hours
was performed. After the water cooling in the process N3, a heat
treatment TH1 at 530° C. for 3 hours was performed (process N31).

[0107] FIG. 5 shows a configuration of a producing process P. In the
producing process P, a cooling condition after extruding is different
from that of the producing process K1. In a process P1, a billet was
heated at 900° C. for 2 minutes, and a rod having an outer
diameter of 25 mm was extruded by the indirect extruder. An extruding
rate was 20 mm/second, and cooling was performed by water cooling. A
cooling rate was about 50° C./second. Thereafter, drawing was
performed to be an outer diameter of 22 mm by a cold drawing process, and
a heat treatment TH1 at 500° C. for 4 hours was performed. In
processes P2 to P4, the extruding and cooling conditions were changed
different from those in the process P1. In the process P2, an extruding
rate was 5 mm/second, and cooling was performed by water cooling. A
cooling rate was about 13° C./second. In the process P3, an
extruding rate was 12 mm/second, and cooling was performed by forced air
cooling. A cooling rate was about 18° C./second. In the process
P4, an extruding rate was 12 mm/second, and cooling was performed by air
cooling. A cooling rate was about 10° C./second.

[0108] FIG. 6 shows a configuration of a producing process Q. In the
producing process Q, a condition of cold drawing is different from that
of the producing process K1. In a process Q1, a billet was heated at
900° C. for 2 minutes, and a rod having an outer diameter of 25 mm
was extruded by the indirect extruder. An extruding rate was 12
mm/second, and cooling was performed by water cooling. A cooling rate was
about 30° C./second. Thereafter, drawing was performed to be an
outer diameter of 20 mm by a cold drawing process, and a heat treatment
TH1 at 490° C. for 4 hours was performed. In a process Q2, drawing
was performed to be an outer diameter of 18.5 mm by a cold drawing
process after the heat treatment TH1 in the process Q1. In a process Q3,
drawing was performed to be an outer diameter of 18 mm by a cold drawing
process after the water cooling in the process Q1, and a heat treatment
TH1 at 475° C. for 4 hours was performed.

[0109]FIG. 7 shows a configuration of a producing process R. In the
producing process R, a pipe was produced. In a process R1, a billet was
heated at 900° C. for 2 minutes, and a pipe having an outer
diameter of 65 mm and a thickness of 6 mm was extruded by a direct
extruder of 3000 tons. An extruding rate was 17 mm/second, and cooling
was performed by rapid water cooling. A cooling rate was about 80°
C./second. Thereafter, a heat treatment TH1 at 520° C. for 4 hours
was performed. In a process R2, drawing was performed to be an outer
diameter of 50 mm and a thickness of 4 mm by a cold drawing process after
the rapid water cooling in the process R1, and then a heat treatment TH1
at 460° C. for 6 hours was performed.

[0110] FIG. 8 shows a configuration of a producing process S. In the
producing process S, a wire was produced. In a process S1, a billet was
heated at 910° C. for 2 minutes, and a rod having an outer
diameter of 11 mm was extruded by the indirect extruder. An extruding
rate was 9 mm/second, and cooling was performed by water cooling. A
cooling rate was about 30° C./second. Thereafter, drawing was
performed to be an outer diameter of 8 mm by a cold drawing process, a
heat treatment TH1 at 480° C. for 4 hours was performed, and wire
drawing was performed to be an outer diameter of 2.8 mm by a cold wire
drawing process. After the process S1, a heat treatment TH2 at
325° C. for 20 minutes was performed (process S2). However, in
case of C1100, when the same heat treatment TH2 is performed,
recrystallization occurs. Accordingly, a heat treatment at 150° C.
for 20 minutes was performed. After the process S1, subsequently, a cold
wire drawing process was performed up to an outer diameter of 1.2 mm
(process S3). After the process S1, a heat treatment TH2 at 350°
C. for 10 minutes was performed, subsequently, a cold wire drawing
process was performed up to an outer diameter of 1.2 mm (process S4), and
a heat treatment TH2 at 420° C. for 0.3 minutes was performed
(process S5). After the water cooling in the process S1, a heat treatment
TH1 at 520° C. for 4 hours was performed, wire drawing was
performed sequentially to be an outer diameter of 8 mm and 2.8 mm by a
cold drawing/wire drawing process, and a heat treatment TH2 at
375° C. for 5 minutes was performed (process S6). After the water
cooling in the process S1, a heat treatment TH1 at 490° C. for 4
hours was performed, wire drawing was performed sequentially to be an
outer diameter of 8 mm, 2.8 mm, and 1.2 mm by a cold drawing/wire drawing
process, and a heat treatment TH1 at 425° C. for 2 hours was
performed (process S7). After the water cooling in the process S1, wire
drawing was performed to be an outer diameter of 4 mm by a cold drawing
process, a heat treatment TH1 at 470° C. for 4 hours was
performed, additionally, wire drawing was performed sequentially to be an
outer diameter of 2.8 mm and 1.2 mm, and a heat treatment TH1 at
425° C. for 1 hour was performed (process S8). After the wire
drawing to the outer diameter of 1.2 mm in the process S8, a heat
treatment TH2 at 360° C. for 50 minutes was performed (process
S9).

[0111] FIG. 9 shows a configuration of a producing process T. The
producing process T is a process of producing a rod and a wire having a
solution-precipitation process, and was performed for comparison with the
producing method according to the embodiment. In producing a rod, a
billet was heated at 900° C. for 2 minutes, a rod having an outer
diameter of 25 mm was extruded by the indirect extruder. An extruding
rate was 12 mm/second, and cooling was performed by water cooling. A
cooling rate was about 30° C./second. Subsequently, heating at
900° C. for 10 minutes was performed, water cooling was performed
at a cooling rate of about 120° C./second, and solution was
performed. Thereafter, a heat treatment TH1 for 520° C. for 4
hours was performed (process T1), and drawing was performed to be an
outer diameter of 22 mm by a cold drawing process (process T2). In
producing a wire, a billet was heated at 900° C. for 2 minutes, a
rod having an outer diameter of 11 mm was extruded by the indirect
extruder. An extruding rate was 9 mm/second, and cooling was performed by
water cooling. A cooling rate was about 30° C./second.
Subsequently, heating at 900° C. for 10 minutes was performed,
water cooling was performed at a cooling rate of about 150°
C./second, and solution was performed. Thereafter, a heat treatment TH1
for 520° C. for 4 hours was performed, drawing was performed to be
an outer diameter of 8 mm by a cold drawing process, wire drawing was
performed to be an outer diameter of 2.8 mm by a cold wire drawing
process, and a heat treatment TH2 at 350° C. for 10 minutes was
performed (process T3).

[0112] As assessment of the high performance copper pipe, rod, or wire
produced by the above-described method, tensile strength, Vickers
hardness, elongation, Rockwell hardness, the number of repetitive bending
times, conductivity, heat resistance, 400° C. high-temperature
tensile strength, and Rockwell hardness and conductivity after cold
compression were measured. In addition, a grain size, a diameter of
precipitates, and a ratio of precipitates having a size of 30 nm or less
were measured by observing a metal structure.

[0113] Measurement of tensile strength was performed as follows. As for a
shape of test pieces, in rods, 14A test pieces of (square root of
sectional area of test piece parallel portion)×5.65 as a gauge
length of JIS Z 2201 were used. In wires, 9B test pieces of 200 mm as a
gauge length of JIS Z 2201 were used. In pipes, 14C test pieces of
(square root of sectional area of test piece parallel portion)×5.65
as a gauge length of JIS Z 2201 were used.

[0114] Measurement of the number of repetitive bending times was performed
as follows. A diameter RA of a bending part was 2×RB (outer
diameter of wire), bending was performed by 90 degrees, the time of
returning to an original position was defined as once, and additionally
bending was performed on the opposite side by 90 degrees, which were
repeated until breaking.

[0115] In measurement of conductivity, a conductivity measuring device
(SIGMATEST D2.068) manufactured by FOERSTER JAPAN limited was used in
case of rods having a diameter of 8 mm or more and cold compression test
pieces. In case of wires and rods having a diameter less than 8 mm,
conductivity was measured according to JIS H 0505. At that time, in
measurement of electric resistance, a double bridge was used. In this
specification, "electrical conductivity" and "conductivity" are used as
the same meaning. Thermal conductivity and electrical conductivity are
intimately related to each other. Accordingly, the higher conductivity
is, the higher thermal conductivity is.

[0116] For heat resistance, test pieces cut so that process-completed rods
have a length of 35 mm (300 mm for tensile test in Table 10 described
later) and compressed test pieces having a height of 7 mm by cold
compression of process-completed rods were prepared, they were immersed
in a salt bath (NaCl and CaCl2 are mixed at about 3:2) of
700° C. for 120 seconds, they are cooled (water cooling), and then
Vickers hardness, a recrystallization ratio, conductivity, an average
grains diameter of precipitates, and a ratio of precipitates having a
diameter of 30 nm or less were measured. The compressed test pieces were
obtained by cutting rods by a length of 35 mm and compressing them using
an Amsler type all-round tester to 7 mm (processing rate of 80%). In the
processes K1, K2, K3, and K4, heat resistance were tested by the test
pieces of the rods. In the process K0 and K01, heat resistance was tested
by the compressed test pieces. A heat treatment was not performed on both
of processed products after compression.

[0117] Measurement of 400° C. high-temperature tensile strength was
performed as follows. After keeping at 400° C. for 10 minutes, a
high-temperature tensile test was performed. A gauge length was 50 mm,
and a test piece was processed by lathe machining to be an outer diameter
of 10 mm.

[0118] Cold compression was performed as follows. A rod was cut by a
length of 35 mm, which was compressed from 35 mm to 7 mm (processing rate
of 80%) by the Amsler type all-round tester. As for rods in the processes
K0 and K01 which were not subjected to the heat treatment TH1, a heat
treatment at 450° C. for 80 minutes was performed as an
after-process heat treatment after the compression, and Rockwell hardness
and conductivity were measured. As for rods in the processes other than
the processes K0 and K01, Rockwell hardness and conductivity were
measured after the compression.

[0119] Measurement of grain size was performed by metal microscope
photographs on the basis of methods for estimating average grain size of
wrought copper in JIS H 0501. Measurement of an average recrystallized
grain size and a recrystallization ratio was performed by metal
microscope photographs of 500-fold magnification, 200-fold magnification,
100-fold magnification, and 75-fold magnification, by selecting
appropriate magnifications according to grain size. Measurement of an
average recrystallization grain size was performed basically by
comparison methods. In measurement of a recrystallization ratio,
non-recrystallized grains and recrystallized grains (including fine
grains) were distinguished from each other, the recrystallized parts were
binarized by image processing software "WinROOF", an area ratio thereof
was set as a recrystallization ratio. When it was difficult to perform
distinguishing from a metal microscope, an FE-SEM-EBSP method was used.
From a grain boundary MAP of 2000-fold magnification or 500-fold
magnification for analysis, grains including a grain boundary having a
directional difference by 15° or more were marked with a Magic
Marker, which were binarized by the image analysis software "WinROOF",
and then a recrystallization ratio was calculated. The measurement limit
is substantially 0.2 μm, and even when there were recrystallized
grains of 0.2 μm or less, they were not applied to the measured value.

[0120] In measurement of diameters of precipitates, transmission electron
images of TEM (Transmission Electron Microscope) of 150,000-fold
magnification and 750,000 fold magnification were binarized by the image
processing software "WinROOF" to extract precipitates, and an average
value of areas of the precipitates was calculated, thereby measuring an
average grain diameter. As for the measurement position, assuming that r
is a radius in the rod or wire, two points at positions of 1r/2 and 6r/7
from the center of the rod or wire were taken, and then an average value
thereof was calculated. In the pipe, assuming that h is a thickness, two
points at positions of 1h/2 and 6h/7 from an inside of the pipe were
taken, and then an average value thereof was calculated. When potential
exists in a metal structure, it is difficult to measure the size of
precipitates. Accordingly, measurement was performed using the rod or
wire in which the heat treatment TH1 was performed on the extruded
material, for example, the rod or wire on which the process K3 was
completed. As for the heat resistance test performed at 700° C.
for 120 seconds, measurement was performed at the recrystallized parts.
Although a ratio of the number of precipitates of 30 nm or less was
performed from each diameter of precipitates, it was determined that
there were large errors about precipitates having a grain diameter less
than 2.5 nm in the transmission electron images of TEM of 150,000-fold
magnification, which were excluded from the precipitates (they were not
applied to calculation). Also in measurement of 750,000-fold
magnification, it was determined that there were large errors about
precipitates having a grain diameter less than 0.7 nm, and thus they were
excluded from the precipitates (not recognized). Centered on the
precipitates having an average grain diameter of about 8 nm, it is
considered that precision of measurement in 750,000-fold magnification
for precipitates smaller than about 8 nm is satisfactory. Accordingly, a
ratio of the precipitates of 30 nm or less indicates accurately 0.7 to 30
nm or 2.5 to 30 nm.

[0121] Measurement of wear resistance was performed as follow. A rod
having an outer diameter of 20 mm was subjected to a cutting process, a
punching process, and the like, and thus a ring-shaped test piece having
an outer diameter of 19.5 mm and a thickness (axial directional length)
of 10 mm was obtained. Then, the test piece was fitted and fixed to a
rotation shaft, and a roll (outer diameter 60.5 mm) manufactured by
SUS304 including Cr of 18 mass %, Ni of 8 mass %, and Fe as the remainder
was brought into rotational contact with an outer peripheral surface of
the ring-shaped test piece with load of 5 kg applied, and the rotation
shaft was rotated at 209 rpm while multi oil was dripped onto the outer
peripheral surface of the test piece (in early stage of test, the test
surface excessively got wet, and then the multi oil was supplied by
dripping 10 mL per day). The rotation of the test piece was stopped at
the time when the number of rotations of the test piece reached 100,000
times, and a difference in weight before and after the rotation of the
test piece, that is, wear loss (mg) was measured. It can be said that
wear resistance of copper alloy is excellent as the wear loss is less.

[0122] Results of the above-described tests will be described. Tables 4
and 5 show a result in the process K0.

[0123] The invention alloy has an average grain size smaller than that of
the comparative alloy or Cr--Zr copper. Tensile strength or hardness of
the invention alloy is slightly higher than that of the comparative
alloy, but an elongation value is clearly higher than that and
conductivity is lower than that. There are a few cases that the pipe,
rod, or wire is used in the extruding-completed state, the pipe, rod, or
wire is used after performing various kinds of processes. Accordingly, it
is preferable that the pipe, rod, or wire be soft in the
extruding-completed state, and conductivity may be low. When the heat
treatment is performed after the cold compression, hardness becomes
higher than that of the comparative alloy. Conductivity of the invention
alloy except for No. 22 alloy in which Sn concentration is high becomes
70% IACS or higher. In the high temperature test of 700° C. using
the compressed test pieces which are not subjected to a heat treatment,
conductivity becomes 65% IACS or higher, that is, conductivity is
improved by about 25% IACS as compared with the case before the heating.
Vickers hardness is 110 or more, and a recrystallization ratio is as low
as about 20%, which are more excellent than those of the comparative
alloy. It is considered that the reason is because most of Co, P, and the
like in a solid solution state are precipitated, conductivity becomes
high, an average grain diameter of the precipitates is as fine as about 5
nm, and thus recrystallization is prevented.

[0125] In C1100, an average grain size at the extruding completion is
large, and created materials of Cu2O are generated. In the invention
alloy, tensile strength, hardness, or the like is slightly higher than
that of the comparative alloy or C1100, and there is a little difference
from that in the process K0. Similarly to the process K0, in this step,
there is no large difference in the performance index I. However,
similarly to the process K0, when the heat treatment is performed after
the cold compression, hardness becomes higher than that of the
comparative alloy, and conductivity becomes 70% IACS or higher. In the
high temperature teat of 700° C. using the compressed test pieces
which are not subjected to a heat treatment, conductivity becomes 65%
IACS or higher, that is, conductivity is improved by about 25% IACS than
the case before heating. Vickers hardness is about 120, and a
recrystallization ratio is as low as about 20%. It is considered that
conductivity is improved by precipitation, the average grain diameter of
the precipitates is as fine as about 5 nm, and thus recrystallization is
prevented.

[0127] In the invention alloy, an average grain size at the extruding
completion is smaller than that of the comparative alloy or C1100, and
tensile strength, Vickers hardness, and Rockwell hardness are
satisfactory. In addition, elongation is higher than that of C1100. In
most of the invention alloy, conductivity is at least 70% of C1100. In
the invention alloy, Vickers hardness after heating at 700° C. and
high-temperature tensile strength at 400° C. are even higher than
those of the comparative alloy or C1100. In the invention alloy, Rockwell
hardness after a cold compression is higher than that of the comparative
alloy or C1100. Wear loss is even lower than that of the comparative
alloy or C1100, and the invention alloy including a large amount of Sn
and Ag is satisfactory. The invention alloy is high strength and high
conductivity copper alloy, and it is preferable that the invention be, if
possible, in the middle of the ranges of the formulas X1, X2, and X3, and
the composition ranges.

[0128] Table 10 shows tensile strength, elongation, Vickers hardness, and
conductivity of rods after heating at 700° C. for 120 seconds
after the process K1 and the process K01.

[0129] In the process K01 in which the heat treatment TH1 is not
performed, tensile strength, elongation, Vickers hardness, and
conductivity are equivalent to those in the process K1 in which the heat
treatment TH1 is performed. In the process K01, even when heating at
700° C. is performed, a recrystallization ratio is low. It is
considered that the reason is because precipitation of Co, P, and the
like occurs to suppress recrystallization. From this result, when heating
at 700° C. for about 120 seconds is performed on a material of the
invention alloy, in which a precipitation is not performed, by brazing or
the like, it is not necessary to perform the precipitation process.

[0130] Tables 11 and 12 show results in the process K2, K3, K4, and K5
together with the result in the process K1.

[0131] In the invention alloy, tensile strength, Vickers hardness, and the
like are satisfactory even in the processes K3 and K5 in which only the
heat treatment TH1 is performed after the extruding. In the invention
alloy, elongation becomes low in the processes K2 and K4 in which a
drawing process is performed after the heat treatment TH1, but tensile
strength or Vickers hardness becomes even higher. In the invention alloy,
an average grain diameter of precipitates in the process K3 is small, and
a ratio of precipitates of 30 nm or less is low, as compared with those
of the comparative alloy. In the invention alloy, mechanical
characteristics such as tensile strength and Vickers hardness are more
satisfactory than those of the comparative alloy or C1100 in the
processes K2, K3, and K4. FIG. 10 is a transmission electron image in the
process K3 of Alloy No. 11. An average grain diameter of the precipitates
is as fine as 3 nm, and the precipitates are uniformly distributed. In
the pipe, rod, or wire in which the invention alloy is produced by the
producing process according to the embodiment, as well as the samples in
the process K3 of Alloy No. 11, as for all the samples, of which data of
diameters of precipitates is described in Table 11, or the
later-described Table 21, 24, 25, and 31, a distance between the most
adjacent precipitates of 90% or higher was 150 nm or less in any area of
1000 nm×1000 nm. In addition, there were 25 or more precipitates in
any area of 1000 nm×1000 nm. That is, it can be said that the
precipitates are uniformly distributed.

[0132] In the invention, regardless of the heat treatment TH1 and rod or
compression-processed material, an average grain diameter of the
precipitates after heating at 700° C. for 120 seconds is as fine
as about 5 nm. Accordingly, it is considered that recrystallization is
suppressed by the precipitates. FIG. 11 is a transmission electron image
after heating at 700° C. for 120 seconds to the
compression-processed material in the process K0 of Alloy No. 11. An
average diameter of the precipitates is as fine as 4.6 nm, there is
substantially no coarse precipitates of 30 nm or more, and the
precipitates are uniformly distributed. When heating at 700° C.
for 120 seconds is performed after the heat treatment TH1, there are fine
precipitates in a state where most of precipitates is not solid-dissolved
again. Accordingly, decrease in conductivity is fixed by 10% IACS or
lower, even as compared with the state after the heat treatment TH1 (see
Test No. 1 and 32 in Tables 11 and 12).

[0133] Tables 13 and 14 show results in the processes L1 to L4 together
with the result in the process K1.

[0134] In the process L1 to the process L4, a heating temperature of a
billet is different from that in the process K1. In the process L2 and
the process L3, with in an appropriate temperature range for heating (840
to 960° C.), tensile strength, Vickers hardness, and the like are
high, similarly to the process K1. On the other hand, in the process L1
lower than the proper temperature, there is a non-recrystallized part at
the extruding completion, and tensile strength and Vickers hardness after
the final process are low. In the process L4 in which the heating
temperature is higher than the proper temperature, an average grain size
at the extruding completion is large, and thus tensile strength, Vickers
hardness, elongation, and conductivity after the final process are low.
It is considered that strength becomes high, since a large amount of Co,
P, and the like are solid-dissolved when the heating temperature is high.

[0135] Tables 15 and 16 show results in the processes P1 to P4 together
with the result in the process K1.

[0136] In the process P1 to the process P4, an extruding rate and a
cooling rate after the extruding are different from those in the process
K1. In the process P1, a cooling rate of which is higher than that in the
process K1, an average grain size at the extruding completion is small as
compared with the result in the process K1, and thus tensile strength,
Vickers hardness, and the like are improved after the final process. In
the process P2 and the process P4, a cooling rate of which is lower than
a proper cooling rate of 15° C./second, an average grain size at
the extruding completion is large as compared with the result in the
process K1, and thus tensile strength, Vickers hardness, and the like
after the final process are decreased. In the process P3 of air cooling,
a cooling rate is higher than a proper rate, and thus tensile strength,
Vickers hardness, and the like after the final process are satisfactory.
From this result, to obtain high strength in the final rod, it is
preferable that a cooling rate be high. It is considered that strength
becomes high, since a large amount of Co, P, and the like are
solid-dissolved when the cooling rate is high. In heat resistance, it is
preferable that a cooling rate be high. In the processes K, L, M, N, Q,
and R of water cooling, in a relationship of an extruding rate (moving
speed of ram, extruding rate of billet) and an extruding ratio H, an
extruding rate is in the range from 45×H-1/3 mm/second to
60×H-1/3 mm/second. On the other hand, in the process P2, an
extruding rate is lower than 30×H-1/3 mm/second. In the
process P1, an extruding rate is higher than 60×H-1/3
mm/second. Comparing P1, P2, and K1, tensile strength of process P2 is
lowest.

[0137] Tables 17 and 18 show the results in the processes M1 to M6
together with the result in the process K1.

[0138] In the process M1 to the process M6, a condition of the heat
treatment TH1 is different from that in the process K1. In the process M1
and M2, in which a heat treatment index TI is smaller than a proper
condition, in the process M4 and M6 in which a heating temperature index
TI is larger than the proper condition, in the process M5, in which a
keeping time of the heat treatment is shorter than a proper time, tensile
strength, Vickers hardness, and the like after the final process are
decreased, as compared with the process M3 and K1 within the proper
condition. In addition, balance of tensile strength, conductivity, and
elongation (product thereof, and performance index I) is deteriorated.
Heat resistance is also deteriorated when the index I is out of the
proper condition.

[0139] Tables 19 and 20 show the results in the processes Q1, Q2, and Q3
together with the result in the process K1.

[0140] In the processes Q1 and Q3, a drawing processing rate after
extruding is different from that in the process K1. In the process Q2, a
drawing process is additionally performed after the process Q1. In the
processes Q1 to Q3, a temperature of the heat treatment TH1 is decreased
according to a drawing process ratio. As the drawing processing rate
after the extruding becomes higher, tensile strength and Vickers hardness
after the final process are improved, and elongation is decreased. When
the drawing process is added after the heat treatment TH1, elongation is
decreased but tensile strength and Vickers hardness are improved.

[0141] Tables 21 and 22 show the results in the processes N1, N11, N2,
N21, N3, and N31.

[0142] In the process N1, the heat treatment TH1 is performed in 2 steps.
In the process N11, the heat treatment TH1 is performed after extruding.
In any one of the processes N1 and N11, satisfactory results are
exhibited similarly to the processes K1 and K3. In the processes N2 and
N21, extruding is direct extruding, and the 2-step heat treatment TH1 is
performed similarly to the processes N1 and N11. Even in case of the
direct extruding, satisfactory results are exhibited similarly to the
processes K1 and K3. Although sizes and the like are different, the rod
of the process N1 has conductivity higher than that of a rod in the
process K1. The processes N3 and N31 are the same processes as the
processes K1 and K3, and a cooling rate after the extruding is high.
Since an average grain size after extruding is small, tensile strength
and Vickers hardness after the final process are satisfactory. In the
processes N2 and N21, a cooling rate is slightly low. Accordingly, an
average grain diameter of precipitates becomes large, and thus tensile
strength and Vickers hardness after the final process are slightly low.

[0144] The processes S1 to S9 are a process of producing a wire. In the
processes S1 to S9, an average grain size of the invention alloy at the
extruding completion is smaller than that of the comparative alloy or
C1100, and thus tensile strength and Vickers hardness are satisfactory.
In the process S2 in which the heat treatment TH2 is performed, the
number of repetitive bending times is improved as compared with that in
the process S1. Also, in the processes S4, S5, S6, and S9 in which the
heat treatment TH2 is performed, the number of repetitive bending times
is improved. Particularly, in the process S9 in which a keeping time of
the heat treatment TH2 is long, strength is slightly low, but the number
of repetitive bending times is large. In the process S3 to the process S6
in which the heat treatments TH1 and TH2 and the wire drawing process are
variously combined, the invention alloy exhibits satisfactory tensile
strength and Vickers hardness. When the heat treatment TH1 is performed
at the heat treatment TH1 completion or in the process close to the
final, strength was low, but particularly flexibility was excellent. In
the processes S7 and S8 in which the heat treatment TH1 is performed
twice, the number of repetitive bending times is particularly improved.
When a total wire drawing processing rate before the heat treatment TH1
is high 75% or higher and the heat treatment

[0145] TH1 is performed, about 15% is recrystallized, but the size of the
recrystallized grains is as small as 3 p.m. For this reason, strength is
slightly decreased, but flexibility is improved.

[0147] The processes R1 and R2 are a process of producing a pipe. In the
processes R1 and R2, the invention alloy exhibits satisfactory tensile
strength and Vickers hardness, and the size of precipitates is small
since a cooling rate after extruding is high.

[0148] Tables 27 and 28 show results in the processes T1 and T2 together
with the results in the processes K3 and K4.

[0149] In the processes T1 and T2, solution-aging precipitation is
performed. In the processes T1 and T2, an average grain size at the
extruding completion is even larger than those in the processes K1 and
K2. Tensile strength, Rockwell hardness, and conductivity in the
processes T1 and T2 are equivalent to those in the processes K3 and K4.
When the processes T1 and T2 are performed using Cr--Zr copper, an
average grain size at the extruding completion is even larger as compared
with the case of performing the processes K3 and K4 using the invention
alloy, tensile strength and Rockwell hardness are slightly low, and
conductivity is slightly high. In the general solution-aging
precipitation material, grains are coarsened for heating at a high
temperature for a long time in solution. On the other hand, Co, P, and
the like are sufficiently made into solution, that is, solid-dissolved,
and thus it is possible to obtain fine precipitates of Co, P, and the
like, depending on the heat treatment thereafter, and aging
precipitation, as compared with the embodiment. However, comparing
strength after the cold wire drawing and the drawing thereafter, the
strength is equivalent to or slightly lower than that of the invention
alloy. It is considered that the reason is because the precipitation
hardening of the solution-aging precipitation material is higher than
that of the invention alloy, but the equivalent strength is exhibited due
to minus offset as much as the grains are coarsened.

[0150] Tables 29 and 30 show a result in the process T3 together with the
result in the process S6.

[0151] The process T3 is a process of producing a wire subjected to
solution-aging precipitation. In the process T3, an average grain size at
the extruding completion is even larger than that in the process S6.
Tensile strength, Vickers hardness, and conductivity in the process T3
are equivalent to those in the process S6, but elongation and repetitive
bending in the process S6 are higher than those in the process T3.
Similarly to the above-described processes T1 and T2, it is considered
that the reason is because the precipitation effect in the process T3 is
higher than that in the process S6, but the equivalent strength is
exhibited due to minus offset as much as the grains are coarsened.
However, elongation and repetitive bending are low since the grains are
coarse.

[0152] Tables 31 and 32 show data at a head portion, a middle portion, and
a tail portion at the same extruding, in the processes K1 and K3 of the
invention alloy and Cr--Zr copper.

[0153] In any one of the processes K1 and K3, Cr--Zr copper has a
difference in an average grain size at the extruding completion at the
head portion and the tail portion, and a large difference in mechanical
characteristics such as tensile strength was found. In any one of the
processes K1 and K3, the invention alloy has a little difference in an
average grain size at the extruding completion at the head portion, the
middle portion, and the tail portion, and mechanical characteristics such
as tensile strength were uniform. In the invention alloy, there is a
little variation in extruding production lot of mechanical
characteristics.

[0154] In the above-described examples, pipes, rods, or wires were
obtained, in which substantially circular or substantially oval fine
precipitates are uniformly dispersed, an average grain diameter of the
precipitates is 1.5 to 20 nm, or at least 90% of the total precipitates
have a size of 30 nm or less, an average grain diameter of most of the
precipitates is in the preferable range of 1.5 to 20 nm, and at least 90%
of the total precipitates have a size of 30 nm or less (see Test No. 32
and 34 in Tables 11 and 12, and transmission electron microscope image in
FIG. 10, etc.).

[0155] Pipes, rods, or wires were obtained in which an average grain size
at the extruding completion is 5 to 75 μm (see Test No. 1, 2, and 3 in
Tables 8 and 9, etc.).

[0156] Pipes, rods, or wires were obtained in which a total processing
rate of the cold drawing/wire drawing process until the heat treatment
TH1 after the hot extruding is over 75%, a recrystallization ratio of
matrix in a metal structure after the heat treatment TH1 is 45% or lower,
and an average grain size of the recrystallized part is 0.7 to 7 μm
(see Test No. 321 and 322 in Tables 23 and 24, etc.).

[0157] Pipes, rods, or wires were obtained in which a ratio of (minimum
tensile strength/maximum tensile strength) in variation of tensile
strength in an extruding production lot is 0.9 or higher, and a ratio of
(minimum conductivity/maximum conductivity) in variation of conductivity
is 0.9 or higher (see Test No. 231, 1, and 232 in Tables 31 and 32,
etc.).

[0158] Pipes, rods, or wires were obtained in which conductivity is 45 (%
IACS) or higher, and a value of the performance index I is 4300 or more
(see Test No. 1 to 3 in Tables 8 and 9, Test No. 171 to 188 and Test No.
321 to 337 in Tables 23 and 24, Test No. 201 to 206, and 313 in Tables 25
and 26, etc.). In addition, pipes, rods, or wires were obtained in which
conductivity is 65 (% IACS) or higher, and a value of the performance
index I is 4300 or more (see Test No. 1 and 2 in Tables 8 and 9, Test No.
171 to 188, and Test No. 321 to 337 in Tables 23 and 24, Test No. 201 to
206, and 313 in Tables 25 and 26, etc.).

[0159] Pipes, rods, or wires were obtained in which tensile strength at
400° C. is 200 (N/mm2) or higher (see Test No. 1 in Tables 8
and 9, etc.).

[0160] Pipes, rods, or wires were obtained in which Vickers hardness (HV)
after heating at 700° C. for 120 seconds is 90 or higher, or at
least 80% of a value of Vickers hardness before the heating (see Test No.
1, 31, and 32 in Tables 11 and 12, etc.). In addition, precipitates in a
metal structure after the heating become larger than those before the
heating. However, an average grain diameter of the precipitates is 1.5 to
20 nm, or at least 90% of the total precipitates are 30 nm or less, a
recrystallization ratio in the metal structure is 45% or lower, and
excellent heat resistance was exhibited.

[0161] Wires were obtained in which flexibility is excellent by performing
a heat treatment at 200 to 700° C. for 0.001 seconds to 240
minutes during and/or after the cold wire drawing process (see Test No.
172, 174, 175, and 176 in Tables 23 and 24, etc.).

[0162] Wires were obtained in which an outer diameter is 3 mm or less, and
flexibility is excellent (see Tables 23 and 24).

[0163] The followings can be said from the above-described examples. In
C1100, there are grains of Cu2O, but the grains do not contribute to
strength since the grains are as large as 2 μm, and an influence on
the metal structure is small. For this reason, high-temperature strength
is low, and a grain diameter is large. Accordingly, it cannot be said
that repetitive bending workability is satisfactory (see Test No. G15 in
Tables 6 and 7, Test No. 23 in Tables 8 and 9, etc.).

[0164] In Alloy No. 41 to 49 of the comparative alloy, Co, P, and the like
do not satisfy the proper range, and balance of the combined amount is
not satisfactory. Accordingly, diameters of the precipitates of Co, P,
and the like are large, and the amount thereof is small. For this reason,
sizes of recrystallized grains are large, strength, heat resistance, and
high-temperature strength are low, and wear loss is large (see Test No.
14 to 22 in Tables 8 and 9, Test No. 48 to 57 in Tables 11 and 12, etc.).

[0165] In the comparative alloy, hardness is low although a cold
compression is performed (see Test No. 14 to 18 in Tables 8 and 9, etc.).
In the invention alloy, sizes of recrystallized grains are small. When
solution is performed as much as the producing process according to the
embodiment and then an aging process is performed, solid-dissolved Co, P,
and the like are finely precipitated and high strength can be obtained.
In addition, most of them are precipitated, and thus high conductivity is
obtained. Since the precipitates are small, a repetitive bending property
is excellent (see Test No. 1 to 13 in Tables 8 and 9, Test No. 31 to 47
in Tables 11 and 12, Test No. 171 to 188 in Tables 23 and 24, etc.).

[0166] In the invention alloy, Co, P, and the like are finely
precipitated. Accordingly, movement of atoms is obstructed, heat
resistance of matrix is also improved by Sn, there is a little structural
variation even at a high temperature of 400° C., and high strength
is obtained (see Test No. 1 and 4 in Tables 8 and 9, etc.).

[0167] In the invention alloy, tensile strength and hardness are high, and
thus wear resistance is high and wear loss is small (see Test No. 1 to 6
in Tables 8 and 9, etc.).

[0168] In the invention alloy, strength of the final material is improved
by performing a heat treatment at a low temperature in the course of the
process. It is considered that the reason is because the heat treatment
is performed after a high plasticity process, and thus atoms are
rearranged according to atomic level. When the heat treatment at a low
temperature is performed at the last, strength is slightly decreased, but
excellent flexibility is exhibited. This phenomenon can not be seen in
the known C1100. Accordingly, the invention alloy is very advantageous in
the field in which flexibility is required.

[0169] When Cr--Zr copper was produced by the producing process according
to the embodiment, a remarkable difference occurred in strength between
the head portion and the tail portion of the extruding after aging, and
strength of the tail portion is badly low. A ratio of the strength is
about 0.8. In addition, characteristics other than heat resistance of the
tail portion are deteriorated. On the other hand, in the invention alloy,
a ratio of the strength is about 0.98, and uniform characteristics are
exhibited (see Tables 31 and 32).

[0170] In addition, the invention is not limited to the configurations of
the above-described various embodiments, and may be variously modified
within the technical scope of the invention. For example, a washing
process may be performed at any part in the course of the process.

INDUSTRIAL APPLICABILITY

[0171] As described above, the high performance copper pipe, rod, or wire
according to the invention has high strength and high conductivity, and
thus is suitable for connectors, bus bars, buss bars, relays, heat sinks,
air conditioner pipes, and electric components (fixers, fasteners,
electric wiring tools, electrodes, relays, power relays, connection
terminals, male terminals, commutator segments, rotor bars or end rings
of motors, etc.). In addition, flexibility is excellent, and thus it is
most suitable for wire harnesses, robot cables, airplane cables, wiring
materials for electronic devices, and the like. In addition,
high-temperature strength, strength after high-temperature heating, wear
resistance, and durability are excellent, and thus it is most suitable
for wire cutting (electric discharging) lines, trolley lines, welding
tips, spot welding tips, spot welding electrodes, stud welding base
points, discharging electrodes, rotor bars of motors, and electric
components (fixers, fasteners, electric wiring tools, electrodes, relays,
power relays, connection terminals, male terminals, commutator segments,
rotor bars, end rings, etc.), air conditioner pipes, pipes for freezers
and refrigerators, and the like. In addition, workability such as forging
and pressing is excellent, and thus it is most suitable for hot forgings,
cold forgings, rolling threads, bolts, nuts, electrodes, relays, power
relays, contact points, piping components, and the like.

[0172] The present application claims the priority of Japanese Patent
Application 2008-087339, the entire contents of which is incorporated
herein by reference.